{"id":296,"date":"2026-05-03T05:47:05","date_gmt":"2026-05-03T05:47:05","guid":{"rendered":"https:\/\/allenglish4u.com\/ielts\/how-something-works\/"},"modified":"2026-05-03T05:47:05","modified_gmt":"2026-05-03T05:47:05","slug":"how-something-works","status":"publish","type":"page","link":"https:\/\/allenglish4u.com\/vi\/ielts\/how-something-works\/","title":{"rendered":"IELTS Vocabulary | Unit 4 \u2014 How Something Works"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">Complete this exercise to practise the vocabulary from <strong>Unit 4: Unit 4 \u2014 How Something Works<\/strong>. Practise describing processes and mechanisms \u2014 a key skill for IELTS Writing Task 1.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Exercise A \u2014 Identify the Object from Its Description (7 objects)<\/h3>\n\n\n<div id=\"ae4u-ex-ielts-how-works-mcq\" class=\"ae4u-ex-mount\" data-exercise-config='{&quot;id&quot;:&quot;ielts-how-works-mcq&quot;,&quot;type&quot;:&quot;multiple-choice&quot;,&quot;section&quot;:&quot;ielts&quot;,&quot;title&quot;:&quot;Unit 4 \\u2014 How Something Works: Identify the Object&quot;,&quot;instructions&quot;:&quot;Read each description and choose the object being described.&quot;,&quot;questions&quot;:[{&quot;question&quot;:&quot;The most important part of this object is a strip of two different metals, one on top of the other. As they heat up, one metal expands faster, so the strip bends and connects with a switch, turning off the power. When it cools down, the switch disconnects again.&quot;,&quot;options&quot;:[{&quot;text&quot;:&quot;thermostat&quot;,&quot;correct&quot;:true},{&quot;text&quot;:&quot;light bulb&quot;,&quot;correct&quot;:false},{&quot;text&quot;:&quot;kettle&quot;,&quot;correct&quot;:false}],&quot;explanation&quot;:&quot;A thermostat uses a bimetallic strip to regulate temperature \\u2014 exactly this mechanism.&quot;},{&quot;question&quot;:&quot;A disc inserted into this device spins quickly. A thin beam of light strikes the disc and converts digital symbols into sounds. The volume can be increased or decreased using a button or dial.&quot;,&quot;options&quot;:[{&quot;text&quot;:&quot;television&quot;,&quot;correct&quot;:false},{&quot;text&quot;:&quot;compact disc player&quot;,&quot;correct&quot;:true},{&quot;text&quot;:&quot;microwave oven&quot;,&quot;correct&quot;:false}],&quot;explanation&quot;:&quot;A compact disc (CD) player uses a laser beam to read digital data on a spinning disc and convert it to sound.&quot;},{&quot;question&quot;:&quot;Liquid and gas are compressed in a hard metal tube. This can be released by pushing a button which opens a valve. When the liquid-gas combination leaves the tube and mixes with oxygen, it rapidly expands.&quot;,&quot;options&quot;:[{&quot;text&quot;:&quot;bicycle pump&quot;,&quot;correct&quot;:false},{&quot;text&quot;:&quot;fire extinguisher&quot;,&quot;correct&quot;:false},{&quot;text&quot;:&quot;aerosol&quot;,&quot;correct&quot;:true}],&quot;explanation&quot;:&quot;An aerosol (spray can) stores pressurised liquid and gas, released through a valve when the button is pressed.&quot;},{&quot;question&quot;:&quot;This object is mainly made of aluminium. As it moves forward, air flows over two horizontal sections. As it accelerates, a vacuum forms over these sections and the object is pulled into the air by this force.&quot;,&quot;options&quot;:[{&quot;text&quot;:&quot;helicopter&quot;,&quot;correct&quot;:false},{&quot;text&quot;:&quot;aeroplane&quot;,&quot;correct&quot;:true},{&quot;text&quot;:&quot;hot air balloon&quot;,&quot;correct&quot;:false}],&quot;explanation&quot;:&quot;An aeroplane generates lift when air moves faster over the wings (the horizontal sections), creating a low-pressure vacuum above them.&quot;},{&quot;question&quot;:&quot;Light enters the glass section and a small door opens when a button is pressed. An aperture adjusts to control the amount of light. The light is absorbed by a sheet of plastic coated in a special chemical, forming an image that can be developed.&quot;,&quot;options&quot;:[{&quot;text&quot;:&quot;projector&quot;,&quot;correct&quot;:false},{&quot;text&quot;:&quot;photocopier&quot;,&quot;correct&quot;:false},{&quot;text&quot;:&quot;camera&quot;,&quot;correct&quot;:true}],&quot;explanation&quot;:&quot;A (film) camera uses a lens, aperture, and light-sensitive film to capture images.&quot;},{&quot;question&quot;:&quot;A sharp blade inside a plastic container rotates very quickly. It chops or grinds anything it touches, which we can then use to produce soup, sauces and dressing.&quot;,&quot;options&quot;:[{&quot;text&quot;:&quot;food processor&quot;,&quot;correct&quot;:true},{&quot;text&quot;:&quot;electric mixer&quot;,&quot;correct&quot;:false},{&quot;text&quot;:&quot;blender&quot;,&quot;correct&quot;:false}],&quot;explanation&quot;:&quot;A food processor has rotating blades that chop and process food for making soups, sauces, etc.&quot;},{&quot;question&quot;:&quot;A small piece of paper is lit with a match. It burns away until the flame ignites a chemical compound inside a cardboard tube. The result is a display of light and colour.&quot;,&quot;options&quot;:[{&quot;text&quot;:&quot;sparkler&quot;,&quot;correct&quot;:false},{&quot;text&quot;:&quot;candle&quot;,&quot;correct&quot;:false},{&quot;text&quot;:&quot;firework&quot;,&quot;correct&quot;:true}],&quot;explanation&quot;:&quot;A firework is ignited via a fuse (paper and chemical compound) and produces a burst of light and colour.&quot;}]}'><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Complete this exercise to practise the vocabulary from Unit 4: Unit 4 \u2014 How Something Works. Practise describing processes and mechanisms \u2014 a key skill for IELTS Writing Task 1. Exercise A \u2014 Identify the Object from Its Description (7 objects)<\/p>","protected":false},"author":1,"featured_media":0,"parent":113,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"page-with-title","meta":{"footnotes":""},"class_list":["post-296","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/allenglish4u.com\/vi\/wp-json\/wp\/v2\/pages\/296","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/allenglish4u.com\/vi\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/allenglish4u.com\/vi\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/allenglish4u.com\/vi\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/allenglish4u.com\/vi\/wp-json\/wp\/v2\/comments?post=296"}],"version-history":[{"count":0,"href":"https:\/\/allenglish4u.com\/vi\/wp-json\/wp\/v2\/pages\/296\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/allenglish4u.com\/vi\/wp-json\/wp\/v2\/pages\/113"}],"wp:attachment":[{"href":"https:\/\/allenglish4u.com\/vi\/wp-json\/wp\/v2\/media?parent=296"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}