托福听力荟萃 09

Human populations near the equator haveevolved dark skin over many generations because of exposure to the fierce raysof the Sun. A similar phenomenon has also occurred in other parts of the animalkingdom. The African grass mouse is a good example. Most mice are______,but the African grass mouse is active during daylight hours. This means that itspends its days searching for food in the semidry bush and______habitats of eastern andsouthern Africa. Its______is______, like a______, which helps it blend in withits environment. Because it spends a lot of time in the intense______sun, the grass mouse has also evolved two separate safeguards against the Sun's______radiation. First, like the populations of humans in this region of the world,the skin of the grass mouse contains lots of______, or dark______. Second, and quite unusual,this mouse has a layer of melanin-pigmented______between its______and skin. This unique "cap" provides an extra measure of protectionfor the grass mouse and three other types of African mouse-like rodents² thatare active during the day. The only other species scientists have identifiedwith the same sort of skull³ adaptation is the white tent-making bat of theCentral American tropics. Although these bats sleep during the day, they do socurled up with their heads exposed to the sun.

 

 

【填空答案】

nocturnal:adj. 夜行的，夜间活动的

scrub: n. 矮树，灌丛

fur: n. 毛皮

stripe: v. 划条纹

chipmunk⁴: n. ［C］花栗鼠

tropical: adj. 热带的

ultraviolet:adj. 紫外线的

melanin: n. ［C］黑色素

pigment¹: n. ［C］色素

tissue: n. ［C］【生】组织

skull: n. ［C］头骨

【听力原文】

Human populations near theequator have evolved dark skin over many generations because of exposure to thefierce rays of the Sun. A similar phenomenon has also occurred in other partsof the animal kingdom. The African grass mouse is a good example. Most mice arenocturnal, but the African grass mouse is active during daylight hours. Thismeans that it spends its days searching for food in the semidry bush and scrubhabitats of eastern and southern Africa. Its fur is striped, like a chipmunk's,which helps it blend in with its environment. Because it spends a lot of timein the intense tropical sun, the grass mouse has also evolved two separatesafeguards against the Sun's ultraviolet radiation. First, like the populationsof humans in this region of the world, the skin of the grass mouse containslots of melanin, or dark pigment. Second, and quite unusual, this mouse has alayer of melanin-pigmented tissue between its skull and skin. This unique"cap" provides an extra measure of protection for the grass mouse andthree other types of African mouselike rodents that are active during the day.The only other species scientists have identified with the same sort of skulladaption is the white tent-making bat of the Central American tropics. Althoughthese bats sleep during the day, they do so curled up with their heads exposedto the sun.

1 pigment   

n.天然色素，干粉颜料

参考例句：

• The Romans used natural pigments on their fabrics and walls.古罗马人在织物和墙壁上使用天然颜料。
• Who thought he might know what the skin pigment phenomenon meant.他自认为可能知道皮肤色素出现这种现象到底是怎么回事。

2 rodents   

n.啮齿目动物( rodent的名词复数 )

参考例句：

• Rodents carry diseases and are generally regarded as pests. 啮齿目动物传播疾病，常被当作害虫对待。 来自《简明英汉词典》
• Some wild rodents in Africa also harbor the virus. 在非洲，有些野生啮齿动物也是储毒者。 来自辞典例句

3 skull   

n.头骨；颅骨

参考例句：

• The skull bones fuse between the ages of fifteen and twenty-five.头骨在15至25岁之间长合。
• He fell out of the window and cracked his skull.他从窗子摔了出去，跌裂了颅骨。

4 chipmunk   

n.花栗鼠

参考例句：

• This little chipmunk is hungry.这只小花栗鼠肚子饿了。
• Once I brought her a chipmunk with a wound on its stomach.一次，我带了只腹部受伤的花栗鼠去找她。