发自于各个探头晶片组边缘并与主声束方向不一致的无关声束称()
A.相控排列
B.声阻抗伪差
C.旁瓣
D.声缺陷
E.侧方声影
参考答案:C
---Have you finished reading The Twilight Saga?
---No, I _______ my homework all day yesterday.
A.was doing
B.doing
C.did
D.have done
明朝年间平定倭寇的将领是()。
A.郑成功
B.朱元璋
C.郑和
D.戚继光