It was not until 1920 ______ regular radio broadcasts began.

李老师

It was not until 1920 ______ regular radio broadcasts began.
A. while
B. when
C. that
D. since
      满分：2  分
3.  An idea has_______ to me.
A. occurred
B. happened
C. come about
D. broken out
      满分：2  分
4.  She thought I was talking about her daughter, ________, in fact, I was talking about my daughter.
A. whom
B. where
C. with
D. while
      满分：2  分
5.  If you go to Xi'an, you will find the palaces there more magnificent than commonly ________.
A. supposing
B. supposed
C. to suppose
D. suppose
      满分：2  分
6.  We were swimming in the lake ______ sud