听写正确文本1-10 (1)

托福听写作业1

正确原文：

This morning I want to tell you about a recent scientific discovery dealing with the relationship between plants and animals. This is about a desert shrub whose leaves can shoot a stream of poisonous resin a distance of six feet. You think it would be safe from all attacks by insects? But a recent study has found one insect, a beetle that can chew its way past the plant's defense system by cutting the main vein that delivers the poison to the leaves. This vein cutting is just one method the beetles used to prepare a safe meal. Another is by cutting a path all the way across the leaves to hold the flow of chemicals. Then they simply eat between the veins of poison. In the past, scientists who studied insect adaptation to plant defenses have focused on chemical responses, that is, how the insects can neutralize or alter the poisonous substances plants produce. What's unique about this chewing strategy is that the beetle is actually exhibiting a behavioral response to the plant's defenses rather than the more common chemical response. It is only after a beetle's survived several encounters with the plant's resin that it learns how to avoid the poison: by chewing through the resin transporting veins on the next leaf it eats, and thus gives itself a safe meal. However, it can take a beetle an hour and a half of careful vein cutting to prepare a small leaf that takes it only a few minutes to eat. So, though the method is effective, it's not very efficient.

生词摘录：

1. shrub: n. 灌木

2. resin: n. 树脂

3. beetle: n. 甲壳虫

4. vein: n. 静脉

5. neutralize: v. 中和

6. alter: v. 改变

托福听写作业2

正确原文：

Human populations near the equator have evolved dark skin over many generations because of exposure to the fiercest rays of the sun. A similar phenomenon has also occurred in other parts of the animal kingdom. The African grass mouse is a good example. Most mice are nocturnal, but the African grass mouse is active during daylight hours. This means that it spends its days searching for food in the semi-dry bush in scrubby habitats of eastern and southern Africa. Its furry stripe's like a chipmunk's, which helps it blend in with its environment. Because it spends a lot of time in the intense tropical sun, the grass mouse has also evolved two separate safeguards against the sun's ultraviolet radiation. First, like the population of humans in this region of the world, the skin of the grass mouse contains lots of melanin, or dark pigment. Second and quite unusual, this mouse has a layer of melanin-pigmented tissue between its skull and skin. This unique cap provides an extra measure of protection for the grass mouse and three other types of African mouse, like rodents that are active during the day. The only other species scientists has identified with the same sort of skull adaptation is the white tent-making bat of the Central American tropics. Although these bats sleep during the day, they do so curled up with their heads exposed to the sun.