问题
选择题
It was 1920 ______ regular radio broadcasts began.
A．while
B．when
C．that
D．since
答案
答案：B
考查定语从句。when 指先行词1920 。
搜题请搜索小程序“爱下问搜题”
It was 1920 ______ regular radio broadcasts began.
A．while
B．when
C．that
D．since
答案：B
考查定语从句。when 指先行词1920 。