由于春节期间的爆竹声不断,一些汽车的警报器 一直响个不停,导致汽车蓄电池电量耗尽。警报器报警主要是因为爆竹声的[ ]
A.音调高
B.响度大
C.音色差
D.频率低
答案:B
The self-contained breathing device should not be used in which situation().
A.Oxygen deficient spaces
B.Compartments containing poisonous vapors
C.Fighting fires that produce heavy smoke
D.Underwater search
鱼粉(饲料用)