2019年5月26日托福阅读真题+题目+答案：Extinction and the Mammoth Steppe

2019年5月26日托福阅读真题+题目+答案：Extinction and the Mammoth Steppe

During the Pleistocene Ice Age that ended 12,000 years ago, many large mammals coexisted in an ecosystem that paleontologist Dale Guthrie dubbed the “mammoth steppe,” an icy prairie too cold, windy, and dry to support more than a few trees. When this ecosystem faded away at the end of the Ice Age, many of its characteristic animals, like the mammoth, the woolly rhino, and the short-faced bear, went extinct, while a new set of megafauna – moose, elk, and bison – invaded Alaska and the Yukon. To understand the varied fates of these big herbivores, Guthrie looks to their digestive systems.

1.Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.

A.Moose, elk, and bison replaced mammoths, woolly rhinos, and short-faced bears as the ecosystem changed at the end of the Ice Age.

B.Many of the animals of the Ice-Age ecosystem, including the mammoth, the woolly rhino, and the short-faced bear, faded away because a new set of megafauna invaded the area.

C.Animals such as mammoth, the woolly rhino, and the short-faced bear were replaced by animals such as moose, elk, and bison as the characteristic megafauna of the Ice Age.

D.When new megafauna species such as moose, elk, and bison invaded Alaska and the Yukon, this ecosystem faded away.

Any creature that lives off leaves or stems must overcome an array of defenses to absorb the nutrients inside. Many plants produce toxins designed to discourage herbivores – and the longer the vegetation grows, the more poisonous it gets. Even the youngest, freshest buds and leaves are full of cellulose, the complex sugar that builds plants’ cell walls. Only bacteria are able to break down cellulose, so every herbivore from rabbit to elephant has evolved ways to nurture cellulose-digesting bacteria in its gut. Wild ruminants like bison and moose ferment (breakdown) their food in a large forestomach called the rumen. ▋Inside this chamber, microbes tear apart plant cells and reconstruct their contents into a complete nutritional package that includes every B vitamin and every essential amino acid. ▋Because they ferment their food before it reaches their intestines, ruminants can eat toxic plants that would sicken or kill a horse. ▋However, their digestion is slow by comparison – and because of the way their guts are designed, it cannot be sped up.▋

2.The word “an array of” in the passage is closest in meaning to

A.various

B.strong

C.tiny

D.well-developed

3.According to paragraph 2, what do all herbivores have in common?

A.They digest their food relatively slowly.

B.They can eat plants that produce different kinds of toxins.

C.They ferment their food before it reaches their intestines.

D.They all need bacteria to break down cellulose.

余下托福阅读真题原文及题目答案省略！

完整版2019年5月26日托福阅读真题+题目+答案：Extinction and the Mammoth Steppe下载，10元有偿！