图示圆轴受扭,则A、B、C三个横截面相对于D截面的扭转角有四种答案:()
A.A
B.B
C.C
D.D
参考答案:B
Chan's restaurant on Baker Street, used to be poorly run, is now a successful business. [ ]
A. that
B. which
C. who
D. where
使用频率复用可以提高频率的利用率、()。