问题

在同一地点发现的远古人类是(  )

A.北京人 山顶洞人

B.元谋人山顶洞人

C.山顶洞人 半坡原始人类

D.河姆渡原始人类半坡原始人类

答案

答案:A

题目分析:元谋人的遗址在云南省元谋县; 半坡原始人类的遗址在山西半坡村;河姆渡原始人类在浙江河姆渡;山顶洞人在北京周口店龙骨山的山洞的洞穴里。故选A

点评:我国是的远古人类遗址最丰富的国家,要仔细观察远古人类遗址示意图,理清他们的空间位置和所在的领域。哪些在长江流域哪些在黄河流域。

单项选择题
单项选择题

It is clear that some chemicals can damage the health of animals and humans. (1) , this is not the only problem that (2) be caused by the careless use of chemicals. Chemicals can also (3) the ecological balance of the environment. If the ecological balance is disturbed, the results can be (4) serious.

The (5) of DDT illustrates the problem. DDT, a chemical which kills insects, at first seemed to be a perfect answer (6) many problems. It would control insects that caused dangerous diseases, (7) insects that caused billions of dollars of damage to crops every year. Governments permitted and even (8) the use of DDT. Farmers in many countries (9) to spray it on their crops. The (10) results were good: Damage to crops (11) down, and profits went up. However, the chemical had effects which the scientists didn’t see in (12) . First, it also killed insects which were the (13) enemies of the harmful insects and which were therefore beneficial to farmers. Second, and perhaps worse, DDT did not kill (14) harmful insect. A few insects had natural resistance to the chemical. They (15) and reproduced in large numbers. In a few years there were large numbers of insects which were not (16) by DDT, and there were (17) insects which could act as natural (18) on these new "super-insects". Finally, it became clear that DDT was not solving the insect problem. In fact, it was making the problem worse. It (19) became necessary to find a second (20) for the effects of the first.

16()

A.effected 

B.affected 

C.damaged 

D.killed