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问题 单项选择题

测量电容引出线接头与分电器活动触点臂安装柱间电阻，电阻无穷大，则故障为（）。

A、活动触点臂安装柱短路

B、电容击穿

C、活动触点臂安装柱断路

D、电容断路

答案

参考答案：A

单项选择题

Questions 81-90 are based on the following passage.


It sounds like a science fiction, but researchers say it’s a scientific fact: Microscopic organisms dubbed "killer algae" are paralyzing fish with unknown toxins and then eating away at their flesh. They might be making people sick, too.
The name given to this single-cell organism, or dinoflagellate, is Pfiesteria piscimorte- literally, "fish killer. " It was discovered at North Carolina State University in 1988, but at the same time, few scientists believed in its existence, much less in its highly unusual predatory nature. But ongoing research has led to international acknowledgment of the phenomenon and, recently, research funding.
Seemingly prompted by an unknown substance secreted by fish, the aggressive creature swims into action. It sends neurotoxins into the water and air, paralyzing a fish’s nervous system, and causing it to gasp for air at the surface. Eventually the fish suffocates. The killer dinoflagellate then attaches itself to the fish and begins sucking away at its flesh. This macabre scenario may help solve several sea mysteries, such as why fishermen report seeing "fish walks" (fish trying to leave the water) and pools of dead fish with holes eaten through them.
Whether humans are affected by the dinoflagellate’s toxin remains to be seen. Researchers think it’s unlikely eating fresh fish are in danger, but anyone with frequent exposure to the creature could be in peril. Several researchers working with the algae have reported bouts of memory loss and disorientation.
To understand the killer algae further, scientists must fully characterize their toxin and determine what stimulates them to attack. They also need to know if the algae are hurting fish populations, and whether pollutants make them more likely to attack.

The passage is primarily concerned with ______.

A. informing readers of different sea creatures
B. describing predatory microscopic organisms
C. solving some long-lasting mysteries about the sea
D. discussing the environment for various fishes
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单项选择题

《污染源自动监控管理办法》已于2005年7月7日由国家环境保护总局2005年第十次局务会议通过，并予公布，自2005年（）起施行。

A、11月1日

B、12月1日

C、11月7日

D、10月1日
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