( )同期录音不要求组成音乐各声部的所有乐器与人声同时演奏或演唱。
参考答案:错
如果x2-3ax+9是一个完全平方式,则a=______.
Lucy liked all the dresses there, but she took the ______one to save as much money as
possible for Project Hope.
A.cheaper
B.more expensive
C.cheapest
D.most expensive