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问题 单项选择题

菊花的种类繁多，形状各异，有绿牡丹、绿云、墨荷、凤凰振羽、帅旗、西湖柳月等。匙球型菊花是菊科草本植物的一种，西湖柳月属于匙球型菊花。菊科草本植物都具有很高的观赏价值，而牡丹花也有很高的观赏价值。
据此，可以推出( )。

A．墨荷属于匙球型菊花
B．作者最喜欢西湖柳月
C．西湖柳月具有很高的观赏价值
D．牡丹花属菊科草本植物

答案

参考答案：C

解析： 由“匙球型菊花是菊科草本植物的一种，西湖柳月属于匙球型菊花”可知西湖柳月是菊科草本植物，再由“菊科草本植物都具有很高的观赏价值”可知西湖柳月具有很高的观赏价值，即C项所述。A、B、D项均无从推知。故选C。

填空题

有限空间场所焊接作业的主要危险是（）、（）、（）、（）。
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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.

7（）

A.as well as 

B.as well 

C.but 

D.also
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