单项选择题

It was not until 1920 ______ regular radio broadcasts began.

A．which
B．when
C．that
D．since
<上一题 目录 下一题>
热门 试题

单项选择题
He wouldn't leave the TV set, ______ he was going to have an important exam the next day.
A．even if
B．as if
C．as though
D．even
单项选择题
There ______ a pen, two pencils and three books on the desk.
A．are
B．is
C．has
D．have
相关试题