治疗蜂螨有效的药物是（）
A.甲酸
B.吡喹酮
C.左旋咪唑
D.三氮脒
E.氨丙啉
参考答案：A
—Do you always spend lots of time playing computer games?
—No, but I spend much time my homework.
A．in; on
B．on; on
C．on; in
D．in; in
