A. 50 B. 55 C. 60 D. 52
A. carried by hand to a fire B. carried or rolled to a fire C. recharged in the field D. used on class "B" fire
A. 正确 B. 错误
A. 台后土压力 B. 自身重量 C. 台内填土 D. 锥坡填土