—_____ is your father doing?
—He is watching TV.[ ]
A. When
B. What
C. How
D. Where
答案:B
药物制剂的配伍可使某些药物产生协同作用。
发音体颤动次数越多,则()
A.声音高
B.声音低
C.声音强
D.与声音的高低无关