目前上海DDN网时钟同步实现()方式
A.一组同步的子网
B.主从同步
C.准同步
D.伪同步
参考答案:B
George once told me that he would visit our house,but,for various reasons,he________so far.
A.didn't
B.hasn't
C.hadn't
D.wouldn't
-Do you know Hong Zhanhui?
-Yes. He’s the college student ____ has moved Chinese people a lot.[ ]
A. who
B. which
C. what
D. whom