A. announce the result of a research on spiders

B. introduce the ways to get rid of the spiders

C. report a new finding of the widow species

D. warn readers against the brown widow

2. From the passage we can conclude that ________．

A. brown widows are spreading northward

B. the brown widow originated from Africa

C. brown widows now can be found in all countries

D. there used to be no brown widows in North America

3. The third paragraph is mainly about ________．

A. the brown widow's web building

B. the characteristics of the brown widow

C. the habitat preferences of the brown widow

D. the brown widow's threat to human beings

4. It can be inferred that ________．

A. brown widows can be killed with any farm chemicals

B. at present people can only control brown widow spiders

C. the brown widow has more poison than the black widow

D. victims bitten by the brown widow needn't see the doctor

答案与解析

　　【文章大意】　一种褐色的毒蜘蛛正在美国蔓延，其危害不容忽视。更糟糕的是，目前还没有消灭它的方法，只能尽力进行控制和预防。

1. 答案　D

解析　推理判断题。文章从这种蜘蛛的渊源谈起，预测了它的蔓延范围，进而介绍了它的生活习性、危害以及控制方法，所以作者意在警告读者当心这种蜘蛛。

2. 答案　A

解析　细节理解题。根据第一段The brown widow spider is continuing its expansion in Southern California and could possibly move northward into Central California可知它们可能会朝北方蔓延。

3. 答案　C

解析　主旨大意题。本段指出了这种蜘蛛经常选择的织网的地方，即主要介绍这种蜘蛛的栖息偏好。

4. 答案　B

解析　推理判断题。最后一段提到还没有掌握控制这种蜘蛛应当使用的化学药品的具体信息，目前的建议是采用控制蜘蛛的一般方法，并提供了一些预防措施，由此可推断目前人们只能控制它们。