托福考试

【单选题】
A、( The adaptations of theAfrican grass mouse to its environment
B、The sleeping habits of theAfrican grass mouse
C、The effect of intense sunlight on the diet of theAfrican grass mouse
D、The habitat of theAfrican grass mouse

网考网参考答案：A
网考网解析：
[听力原文]44-46 Human population 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 squired 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 have identified with the same sort of skull of that occasion is the white camp-making bat of the Central American tropic. Although these bats sleep during the day, they do so curled up with their head exposed to thesun. 44. What is the speaker mainly discussing document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>