So how many species of frogs are there in the world? " About 4,000 species are now known to scientists. They are different in size. The smallest frog is less than half an inch and the biggest frog is nearly a foot long. The biggest frog is the Goliath frog. "It's found in ...
正确答案:C 解析:本题的关键是数字信息的听辨和记录。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 resulte...
It is a natural process of animal species to become extinct (e.g. dinosaurs, dodos etc.). There is no reason why people should try to stop this from happening. Do you agree or disagree? Give reasons for your answer and include any relevant examples from your own knowledge or experience....
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“We could have kind of a Dow Jones index of the environment,” Fisher said. No simple answer 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 ...
根据第三段“Not only can eDNA identify thousands of species in a single sample of water, but the technique can be used in the field to assess biodiversity in water and other environments faster, more comprehensively, yet also much less harmfully than traditional physical surveys.(eDNA 不仅可以...
解答 答案:D.根据真正主语how many animal species are in the danger of dying out可见空白处应为形式主语,纵观选项,唯有it可担当形式主语,故选D.注意区分主语从句B选项what…is 从句,就对了. 点评 本题考查it 形式主语,结合语义的基础上便能选出正确答案,同时要注意与主语从句不要混淆.练习...
With 1 million insect species named, this suggests that 80% remain to be discovered and that a greater focus should be placed on less-studied taxa such as many families of Coleoptera, Diptera, and Hymenoptera and on poorly sampled parts of the world. DNA tools have revealed many new species...
What type of skeleton do fish have? How many digestive glands does a starfish have? How many classes are in the phylum Arthropoda? Are cartilaginous fish invertebrates? How many species of Chlorophyta exist? How many marine organisms are in the Bahamas? Are hagfish bony or cartilaginous fish?
Nowadays, many wild animals around the world are in danger. Some kinds of them are dying out at an alarming rate (以惊人的速度). Between 150 and 200 species (物种) disappear every day. To make us aware of the serious problem and help save the animals in danger before it’s too late...