`); let searchUrl = `/search/`; history.forEach((elem) => { prevsearch.find('#prevsearch-options').append(`
${elem} `); }); } $('#search-pretype-options').empty(); $('#search-pretype-options').append(prevsearch); let prevbooks = $(false); [ {title:"Recently Opened Textbooks", books:previous_books}, {title:"Recommended Textbooks", books:recommended_books} ].forEach((book_segment) => { if (Array.isArray(book_segment.books) && book_segment.books.length>0 && nsegments<2) { nsegments+=1; prevbooks = $(`
${book_segment.title} `); let searchUrl = "/books/xxx/"; book_segment.books.forEach((elem) => { prevbooks.find('#prevbooks-options'+nsegments.toString()).append(`
${elem.title} ${ordinal(elem.edition)} ${elem.author} `); }); } $('#search-pretype-options').append(prevbooks); }); } function anon_pretype() { let prebooks = null; try { prebooks = JSON.parse(localStorage.getItem('PRETYPE_BOOKS_ANON')); }catch(e) {} if ('previous_books' in prebooks && 'recommended_books' in prebooks) { previous_books = prebooks.previous_books; recommended_books = prebooks.recommended_books; if (typeof PREVBOOKS !== 'undefined' && Array.isArray(PREVBOOKS)) { new_prevbooks = PREVBOOKS; previous_books.forEach(elem => { for (let i = 0; i < new_prevbooks.length; i++) { if (elem.id == new_prevbooks[i].id) { return; } } new_prevbooks.push(elem); }); new_prevbooks = new_prevbooks.slice(0,3); previous_books = new_prevbooks; } if (typeof RECBOOKS !== 'undefined' && Array.isArray(RECBOOKS)) { new_recbooks = RECBOOKS; for (let j = 0; j < new_recbooks.length; j++) { new_recbooks[j].viewed_at = new Date(); } let insert = true; for (let i=0; i < recommended_books.length; i++){ for (let j = 0; j < new_recbooks.length; j++) { if (recommended_books[i].id == new_recbooks[j].id) { insert = false; } } if (insert){ new_recbooks.push(recommended_books[i]); } } new_recbooks.sort((a,b)=>{ adate = new Date(2000, 0, 1); bdate = new Date(2000, 0, 1); if ('viewed_at' in a) {adate = new Date(a.viewed_at);} if ('viewed_at' in b) {bdate = new Date(b.viewed_at);} // 100000000: instead of just erasing the suggestions from previous week, // we just move them to the back of the queue acurweek = ((new Date()).getDate()-adate.getDate()>7)?0:100000000; bcurweek = ((new Date()).getDate()-bdate.getDate()>7)?0:100000000; aviews = 0; bviews = 0; if ('views' in a) {aviews = acurweek+a.views;} if ('views' in b) {bviews = bcurweek+b.views;} return bviews - aviews; }); new_recbooks = new_recbooks.slice(0,3); recommended_books = new_recbooks; } localStorage.setItem('PRETYPE_BOOKS_ANON', JSON.stringify({ previous_books: previous_books, recommended_books: recommended_books })); build_popup(); } } var whiletyping_search_object = null; var whiletyping_search = { books: [], curriculum: [], topics: [] } var single_whiletyping_ajax_promise = null; var whiletyping_database_initial_burst = 0; //number of consecutive calls, after 3 we start the 1 per 5 min calls function get_whiletyping_database() { //gets the database from the server. // 1. by validating against a local database value we confirm that the framework is working and // reduce the ammount of continuous calls produced by errors to 1 per 5 minutes. return localforage.getItem('whiletyping_last_attempt').then(function(value) { if ( value==null || (new Date()) - (new Date(value)) > 1000*60*5 || (whiletyping_database_initial_burst < 3) ) { localforage.setItem('whiletyping_last_attempt', (new Date()).getTime()); // 2. Make an ajax call to the server and get the search database. let databaseUrl = `/search/whiletype_database/`; let resp = single_whiletyping_ajax_promise; if (resp === null) { whiletyping_database_initial_burst = whiletyping_database_initial_burst + 1; single_whiletyping_ajax_promise = resp = new Promise((resolve, reject) => { $.ajax({ url: databaseUrl, type: 'POST', data:{csrfmiddlewaretoken: "7drtHV0ZXjgYoc0800ERgalnNbNhDlf930jK1SW6hrIOtpJjJjPAuv0XNX6WZJP5"}, success: function (data) { // 3. verify that the elements of the database exist and are arrays if ( ('books' in data) && ('curriculum' in data) && ('topics' in data) && Array.isArray(data.books) && Array.isArray(data.curriculum) && Array.isArray(data.topics)) { localforage.setItem('whiletyping_last_success', (new Date()).getTime()); localforage.setItem('whiletyping_database', data); resolve(data); } }, error: function (error) { console.log(error); resolve(null); }, complete: function (data) { single_whiletyping_ajax_promise = null; } }) }); } return resp; } return Promise.resolve(null); }).catch(function(err) { console.log(err); return Promise.resolve(null); }); } function get_whiletyping_search_object() { // gets the fuse objects that will be in charge of the search if (whiletyping_search_object){ return Promise.resolve(whiletyping_search_object); } database_promise = localforage.getItem('whiletyping_database').then(function(database) { return localforage.getItem('whiletyping_last_success').then(function(last_success) { if (database==null || (new Date()) - (new Date(last_success)) > 1000*60*60*24*30 || (new Date('2023-04-25T00:00:00')) - (new Date(last_success)) > 0) { // New database update return get_whiletyping_database().then(function(new_database) { if (new_database) { database = new_database; } return database; }); } else { return Promise.resolve(database); } }); }); return database_promise.then(function(database) { if (database) { const options = { isCaseSensitive: false, includeScore: true, shouldSort: true, // includeMatches: false, // findAllMatches: false, // minMatchCharLength: 1, // location: 0, threshold: 0.2, // distance: 100, // useExtendedSearch: false, ignoreLocation: true, // ignoreFieldNorm: false, // fieldNormWeight: 1, keys: [ "title" ] }; let curriculum_index={}; let topics_index={}; database.curriculum.forEach(c => curriculum_index[c.id]=c); database.topics.forEach(t => topics_index[t.id]=t); for (j=0; j
Solutions
Textbooks
`); } function build_solutions() { if (Array.isArray(solution_search_result)) { const viewAllHTML = userSubscribed ? `View All` : ''; var solutions_section = $(` Solutions ${viewAllHTML} `); let questionUrl = "/questions/xxx/"; let askUrl = "/ask/question/xxx/"; solution_search_result.forEach((elem) => { let url = ('course' in elem)?askUrl:questionUrl; let solution_type = ('course' in elem)?'ask':'question'; let subtitle = ('course' in elem)?(elem.course??""):(elem.book ?? "")+" "+(elem.chapter?"Chapter "+elem.chapter:""); solutions_section.find('#whiletyping-solutions').append(` ${elem.text} ${subtitle} `); }); $('#search-solution-options').empty(); if (Array.isArray(solution_search_result) && solution_search_result.length>0){ $('#search-solution-options').append(solutions_section); } MathJax.typesetPromise([document.getElementById('search-solution-options')]); } } function build_textbooks() { $('#search-pretype-options').empty(); $('#search-pretype-options').append($('#search-solution-options').html()); if (Array.isArray(textbook_search_result)) { var books_section = $(` Textbooks View All `); let searchUrl = "/books/xxx/"; textbook_search_result.forEach((elem) => { books_section.find('#whiletyping-books').append(` ${elem.title} ${ordinal(elem.edition)} ${elem.author} `); }); } if (Array.isArray(textbook_search_result) && textbook_search_result.length>0){ $('#search-pretype-options').append(books_section); } } function build_popup(first_time = false) { if ($('#search-text').val()=='') { build_pretype(); } else { solution_and_textbook_search(); } } var search_text_out = true; var search_popup_out = true; const is_login = false; function pretype_setup() { $('#search-text').focusin(function() { $('#search-popup').addClass('show'); resize_popup(); search_text_out = false; }); $( window ).resize(function() { resize_popup(); }); $('#search-text').focusout(() => { search_text_out = true; if (search_text_out && search_popup_out) { $('#search-popup').removeClass('show'); } }); $('#search-popup').mouseenter(() => { search_popup_out = false; }); $('#search-popup').mouseleave(() => { search_popup_out = true; if (search_text_out && search_popup_out) { $('#search-popup').removeClass('show'); } }); $('#search-text').on("keyup", delay(() => { build_popup(); }, 200)); build_popup(true); let prevbookUrl = `/search/pretype_books/`; if (is_login) { $.ajax({ url: prevbookUrl, method: 'POST', data:{csrfmiddlewaretoken: "7drtHV0ZXjgYoc0800ERgalnNbNhDlf930jK1SW6hrIOtpJjJjPAuv0XNX6WZJP5"}, success: function(response){ previous_books = response.previous_books; recommended_books = response.recommended_books; build_popup(); }, error: function(response){ console.log(response); } }); } else { let prebooks = null; try { prebooks = JSON.parse(localStorage.getItem('PRETYPE_BOOKS_ANON')); }catch(e) {} if (prebooks && 'previous_books' in prebooks && 'recommended_books' in prebooks) { anon_pretype(); } else { $.ajax({ url: prevbookUrl, method: 'POST', data:{csrfmiddlewaretoken: "7drtHV0ZXjgYoc0800ERgalnNbNhDlf930jK1SW6hrIOtpJjJjPAuv0XNX6WZJP5"}, success: function(response){ previous_books = response.previous_books; recommended_books = response.recommended_books; build_popup(); }, error: function(response){ console.log(response); } }); } } } $( document ).ready(pretype_setup); $( document ).ready(function(){ $('#search-popup').on('click', '.search-view-item', function(e) { e.preventDefault(); let autoCompleteSearchViewUrl = `/search/autocomplete_search_view/`; let objectUrl = $(this).attr('href'); let selectedId = $(this).data('objid'); let searchResults = []; $("#whiletyping-solutions").find("a").each(function() { let is_selected = selectedId === $(this).data('objid'); searchResults.push({ objectId: $(this).data('objid'), contentType: $(this).data('contenttype'), category: $(this).data('category'), selected: is_selected }); }); $("#whiletyping-books").find("a").each(function() { let is_selected = selectedId === $(this).data('objid'); searchResults.push({ objectId: $(this).data('objid'), contentType: $(this).data('contenttype'), category: $(this).data('category'), selected: is_selected }); }); $.ajax({ url: autoCompleteSearchViewUrl, method: 'POST', data:{ csrfmiddlewaretoken: "7drtHV0ZXjgYoc0800ERgalnNbNhDlf930jK1SW6hrIOtpJjJjPAuv0XNX6WZJP5", query: $('#search-text').val(), searchObjects: JSON.stringify(searchResults) }, dataType: 'json', complete: function(data){ window.location.href = objectUrl; } }); }); });
FAQs
Fish swim by flexing their bodies and tail back and forth. Fish stretch or expand their muscles on one side of their body while relaxing the muscles on the other side. This motion moves them forward through water. Fish also use their back fin, called the caudal fin, to help push them through water.
Do fish have fins for swimming? ›
The caudal fin or tail is not the only fin a fish uses to swim. For example, the pectoral fins, which sit almost horizontally on the body of rapidly swimming oceanic fish, along with the pelvic fins, play an important role by acting as stabilizers to prevent the fish from rolling as it moves through the water.
How do fish swim with the help of wings? ›
Fins are flat and thin body parts attached to the body of a fish, like wings of a bird. Fish use fins to swim in water and it also provides balance to the body of the fish.
How does a fish move? ›
Fins are also present in the body which help in movement and balance of the body. Fish also have strong muscles which make the front part of the body curve to one side and the tail fins part swing on the opposite side in the water. This makes a sharp move and pushes the body of the fish forward to swim in the water.
Do fish live in or on water? ›
Hint: Fish is an organism that lives only in water and cannot survive outside water, i.e. they are aquatic animals, which live, move as well as reproduce in water.
Do fish have to swim? ›
Many fish must swim constantly in order that water is always flowing past their gills. This is the case for most sharks, which is why they cannot survive when thrown back into the sea following the removal of their fins by fishers supplying the shark fin soup market.
Can you swim with fins? ›
Swim training fins are one of the most versatile in the world of swimming and swim equipment. Swimming with fins helps teach you to swim more efficiently, strengthens the legs, and can help you master better kicking mechanics.
Does cod fish have fins? ›
Codfishes are characterized by having a single barbel on the middle of the chin. They have 1-3 dorsal fins and 1-2 anal fins. They have no spines, and the tail fin is small and rounded.
Why are fish so fast? ›
overlapping scales and a mucus or slime boundary. layer reduces drag, greater tail area can give more. thrust, and small fins and finlets divert water flow. along the fish's body.
What does a fish see? ›
Fish have a narrow cone (about 30 degrees) of binocular vision to the front and directly above their snouts. Outside this cone, fish see only how wide and tall an object is-they can't tell how far away it is, or how deep it is. Fish are nearsighted. That is, objects at a dis- tance aren't seen clearly.
Flying Fish Do Not Fly
However, one type of fish sure can glide like champs, and do so with fins evolved to serve as wings. Flying fishes' pectoral fins are long, reinforced affairs that when locked open sure do look and act like wings, catching air and using the very same aerodynamics to stay aloft for long periods.
How do fish live in water? ›
Fish do not breathe air. They get the oxygen they need from the water they live in. Fish have special filters in the sides of their body called 'gills' that act as their 'lungs'.
How do fish propel in water? ›
The contractions “bend” the fish's body, creating a wave that pushes against the water. The wave also moves the fish's tail fin back and forth, which pushes against the water like an oar, generating most of the forward push. But not every fish pushes in the same way.
How do fish feel to touch? ›
An analysis of the cellular structures of the fin revealed the presence of cells that closely resemble Merkel cells, which are associated with nerve endings in the skin of mammals and are essential for touch. "Like us, fish are able to feel the environment around them with their fins.
Do fish realize they are in water? ›
No fish don't know they're in water just like many animals don't know they're in land. There have been many cases fishes crossing land water barrier and entering land and dying. Also huge fishes such as whales have been found alive in beaches and many times have to be rescued with help from humans.
How do fish just appear in water? ›
Or a river may have flooded long ago and briefly flowed into low-lying land to create a populated lake. Some lake residents are even descended from ancestors that crossed from one lake to another. While most fish can't travel very far over the land, their eggs will survive for several hours out of water.
How do fish swim and not sink? ›
The trick is the swim bladder, which is basically like an air-inflated balloon that can expand and contract depending on how much gas is inside. When the swim bladder expands it will increase in volume and therefore displace more water. This increases the fish's buoyancy and it will float upward.
How do fish run out of oxygen in water? ›
In places such as swamps and pools, the absence of wind and water currents prevents the mixing of the oxygen-rich upper layer with the rest of the water column. [1] In other places, an overabundance of aquatic animals or decomposing matter depletes oxygen through increased consumption.
![VIDEO solution: Which Of The Following Statement Is Or Are Incorrect? *
1 point
[A]. A fish swims in water by moving its tail from side to side.
[B]. The effect of left side of tail on water is compensated by the fish by turning its head to the right side (2024)](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/h8AAvMB+NzmkbcAAAAASUVORK5CYII=)