Tietze病治疗首选()
A.抗生素的应用
B.手术切除肋软骨
C.理疗
D.对症治疗
E.以上都不是
参考答案:D
计算:(-5a2b)(-3a)=______;(x-3y)(-6x)=______.
Lucy is ______ of the two. [ ]
A. quiet
B. quietest
C. quieter
D. the quieter