当a>0时,a34•a-12÷3a4=a34•a-12• a-43=a34-12-43=a-112
故答案为a-112
声强法测量对()环境无特殊要求,并可在()测量,既方便又迅速。
A vessel with a large GM will().
A.have a small amplitude of roll in heavy weather
B.tend to ship water on deck in heavy weather
C.be subject to severe racking stresses
D.be less likely to have cargo shift