2021年广东省广州市华南师大附中高考英语模拟试卷（5月份）（附详解）.docx

第 =page 2 2页，共 =sectionpages 2 2页 第 =page 1 1页，共 =sectionpages 1 1页 2021年广东省广州市华南师大附中高考英语模拟试卷（5月份） 一、阅读理解（本大题共15小题，共37.5分） A There are as many different types of sleeper as there are animal varieties on the planet. There are dozers,dreamers, nappers and hardcore dead-to-the-worlders. Dolphins Dolphins face a bit of a problem as they spend their whole lives in the water,but as mammals they need to breathe oxygen to survive. How do they juggle this when unconscious？Dolphins shut down half of their brain, which rests, while the other half is alert and looking out for any potential dangers. As they do this, the dolphin will lie on the surface of the water in a behaviour known as logging. Elephants Elephants tend to nod off for a few minutes at a time throughout the day. Elephants only manage about two hours of sleep per day, and thats not even a concentrated block of shuteye. They tend to nod off for a few minutes at a time throughout the day. Possibly because of this, most of their sleeping is done standing up,with just the occasional recumbent （伏卧的） sleep. Spiders Of course spiders have to be awkward. Even though animals sleep in a vast array of different ways, all of them, even bacteria, follow a 24 hour cycle, known as a circadian rhythm that is dictated by the rotation of the Earth. But scientists have discovered that certain types of orb-weaving spiders simply dont bother with this. Their body clocks follow a 17，18 or 19 hour cycle. Scientists arent exactly sure how the spider can even exist with this completely different body clock. Koalas One problem with trying to work out a creatures sleeping habits is the difficulty of identifying what is actual sleep. Its easier to study captive animals,but they can behave in a completely different manner to their cousins in the wild. Koalas studied in zoos were thought to sleep for up to 22 hours a day, but a more detailed study, looking at animals in the wild too, revealed that they in fact sleep for around 14