In the construction site, the engineer ______ must be able to communicate his ideas to others rapidly and correctly.

A．in particular

B．in special

C．in detail

D．in generally

某船Δ=12000t，若垂向移货400t，移动前后的货物重心高度分别为15.0m和7.0m，则GM的改变量为（）m。

A.0.10

B.0.12

C.0.21

D.0.27