牛黄解毒片与哪种药合用会降低药物疗效（）
A.庆大霉素
B.青霉素
C.四环素
D.维生素
E.红霉素
参考答案：C
平行四边形ABCD中，AB=6cm，BC=12cm，对边AD和BC之间的距离是4cm，则对边AB和CD间的距离是______cm．
— When was Michael Jackson born?
— He was born in Indiana _____ August 29th, 1958.
A. at
B. in
C. on
D. for
