How did Earth get so many species(物种)? For thousands of years, people wond-ered. In the 1840s, one naturalist (博物学家) had an idea. His name was Charles Darwin. He spent his whole life studying animals and insects. Darwin thought that new species developed slowly, as populations of...
根据原文“Around 380 million years ago,only 300 species groups were left in existence”,可以判断C是正确选项。 知识模块:句子听辨 听力原文:During the past 1. 65 million years, there have been four major episodes of global cooling, which resulted in great migrations of animals and plants. Yet,...
Though taxonomists have been cataloguing plants and animals for more than 250 years, they still have no exact answer to the question, “How many species are on Earth?”“It’s a very simple question, but we have no simple answer,” Fisher said. One of the reasons we can’t get an...
Some people say it is acceptable to use animals for our benefit, others say it is wrong to exploit them. Discuss both points of view and give your opinion. Give reasons for your answer and include any relevant examples from your own knowledge or experience. Write at least 250 words. Task...
aWhich human factor most seriously threatens the survival of animals? 正在翻译,请等待...[translate] aHabitat destruction. 正在翻译,请等待...[translate] aHow many species of birds, mammals, invertebrates, and plants are endangered? 正在翻译,请等待...[translate]...
How many new species of monkeys have been identified in Brazil alone over the last year? A. Eight. B. Nine. C. Ten. D. Eleven.正确答案:B解析:事实细节题。本题询问去年只在巴西一国就新发现多少种猴子。本题答案可以从文章第二段末句得出。选项B为正确答案。 相关知识点: ...
Why the species is able to delay gratification is a bit of a mystery.For humans,scientists believe the quality strengthens social bonds.An example would be when you see someone wait for a partner to eat.Delayed gratification can also be a function of tool-building animals,who need to make ...
1. What is the ultimate statistical invariances of turbulence? 湍流的最终统计不变性是什么? 2. How can we break the current limit of energy conversion efficiencies? 我们如何突破当前的能量转换效率极限? 3. How can we develop manufacturing systems on Mars?
对食品安全问题不放心4个月，伴反复检查、苦恼2个月。具体表现为：不敢在外边的饭店吃饭，担心饭店的菜洗不干净，炒菜用的油是泔水。不敢吃牛肉干，害怕得疯牛病，不敢吃猪肉，猪饲料中激素太多。尤其是“福寿螺”事件后，不仅小龙虾之类，甚至海鲜类的食物也拒绝吃了。米饭也是尽能少吃，因为大米上的农药实在...
Sadly, our ability to multiply has threatened the existence of countless other mammals on Earth, Order Artiodactyla: Approximately 356 Species Members of order Artiodactyla are also known as even-toed ungulates — which is another way of referring to animals that have hooves. They constitute the ...