软件产生正弦波,对于25Hz的正弦波,每个周期就有约()个样本。
A.400
B.410
C.430
D.440
参考答案:D
Bob has short, brown hair. _____________ eyes are brown. [ ]
A. His
B. He
C. Her
D. She
混凝土坝发生滑动破坏的形式有()。
A.表层滑动
B.浅层滑动
C.中层滑动
D.底层滑动
E.深层滑动