发电机组的排气管路不宜多于2个90度弯，当排气管路过长或90度弯头大于2个时排气管应加大截面积。
参考答案：对
噪声性听力损伤和噪声聋分级标准中：中度听力损伤时听力下降
A．41～55dBB．24～50dBC．26～40dBD．56～70dBE．71～90dB
Who are Lisa and Tim ________?[ ]
A. talk to
B. talking to
C. talk
D. talking
