在现场燃气、热力、给排水管道()m范围内挖土时,必须在燃气、热力、给排水单位人员的监护下采取人工开挖。
A. 0.5
B. 1.0
C. 1.5
D. 2.0
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按照生产性噪声种类,大型发电机发出的噪声属于()噪声。
A. 空气动力
B. 机械性
C. 电磁性
D. 振动性
煤矿井下矿用防爆电气设备外壳的明显处都有在这种场所使用电气设备的特别标志“()”。
A. IP
B. FB
C. dB
D. Ex
Section A
Directions: This section is to test your ability to understand short dialogues. There are 5 recorded dialogues in it. After each dialogue, there is a recorded question. The dialogues and the questions will be spoken only once. When you hear a question, you should decide on the correct answer from the 4 choices A , B, C, and D.
(1)
A. 6:30.
B. 7:00.
C. 7:15.
D. 7:30.
以下情况不属于突水预兆的是()。
A. 煤层变潮湿、松软
B. 工作面气温升高
C. 有时煤帮出现铁锈色水迹
D. 矿压增大,发生片帮、冒顶及底鼓