鼓室积液时鼓室图为（）。
A.A型
B.B型
C.C型
D.As型
E.Ad型
参考答案：B
The buses, ________ were already full, were surrounded by an angry crowd.
A．most of them
B．which most
C．most of which
D．that most
集团公司使用的MG550/1380采煤机泵站电机电压是（）V。
A、380V
B、1140V
C、660V
D、3300V
