一辆汽车性能的优劣，其油耗标准非常重要，而影响汽车油耗标准最主要的因素是其在行进

读短文，判断正(T)误(F)。

     Long ago there were many animals on the earth. But now we can't see some of the animals, because

they died, such as(例如) dinosaurs. Some animals died of natural disasters(死于天灾). But some died

because man did bad things to the nature(自然界). People cut trees and built tall buildings. So some

animals had no food to cat, no homes to live in or clean water to drink. Man killed animals, too. Now

some animals are dying(死) out, such as pandas and antelopes(藏羚羊). If we don't want the animals to

disappear(消失) from the world, we should protect(保护)  the nature and animals.

( ) 1. Once there were many animals in the world.

(     ) 2. Some animals died, because the other animals killed them.

(     ) 3. Some animals died, because man did bad things to the nature.

(     ) 4. We are going to lose pandas if we don't protect them.

(     ) 5. Some animals are disappearing.

定金是合同当事人一方预先支付给对方的款项，其目的在于担保合同( )的实现。

A．债权

B．债务

C．主体

D．内容

小儿风寒感冒，咳嗽较重者，应首选

A．杏苏散
B．桑菊饮
C．止嗽散
D．贝母瓜蒌散
E．三拗汤

不同的水样有不同的采样时间和频率，地下水水质的采样时间和频率通常为（）.

A.每月采样1次

B.3个月采样1次

C.半年采样1次

D.1年采样1次

E.丰、枯水期各采样1次

炉子熄火后，重新点燃为什么先要用蒸汽吹扫？