A.聆聽油船船艙處有無異響 B.觀察油船船艙處有無煙霧冒出 C.觸摸油船船艙處有無發(fā)熱,輕聞油船附近空氣有無異味 D.以上方法皆是
A.1t B.2t C.3t D.4t
A.20% B.1倍 C.50% D.30%