问题
单项选择题
测量单芯电缆金属护层接地电流的目的是（）。
A.判别金属护层是否断路；
B.判别金属护层感应电压限制器是否击穿；
C.判别电缆主绝缘优劣，
D.判别外护套绝缘电阻是否良好。
答案
参考答案：B
搜题请搜索小程序“爱下问搜题”
测量单芯电缆金属护层接地电流的目的是（）。
A.判别金属护层是否断路；
B.判别金属护层感应电压限制器是否击穿；
C.判别电缆主绝缘优劣，
D.判别外护套绝缘电阻是否良好。
参考答案：B
| 阅读短文，用方框中所给词的正确形式填空。 | |
| |
| There is something people didn't understand in the sky. The USAF (美国空军) 1 used the words"Unidentified Flying Object" to describe them. Today 2 uses the term UFO. When people see a UFO, it is 3 a weather balloon (气球) or an airplane. But the Center 4 UFO Studies continues to receive 5 of reports every year． In 1947 a businessman and pilot, Kenneth Arnold. 6 near Mount Rainier, Washington when he saw nine shiny, round objects flying through the air. He told a newspaper reporter that they 7 like "pie plates skipping over water". The reporter used the words "flying saucer" in his-story and today that 8 a popular name' for UFOs. Now in different countries, many people 9 the UFOs. Some people make mistakes when they say they have seen UFOs. But people still can't 10 UFOs clearly. It may take many years to find a clear answer. |