B not until = if .not.
原句可写为：I will lend you the book if i have finished reading it.
可理解为 主将从现.I 后接的是主句是将来时UNTIL 后是从句是现在时.
C so she had to wait 因为前面的动作发生在这个动作之前,所以前一个动作应是过去的过去,是过去完成时,排除AB ,CD的区别和上一题中的理解类似.
D ever since 1977.由此可知应该选现在完成时,排除AB
The CCTV has broadcast English programme .
The English programme has been broadcast on the CCTV.
上两句都是对的,C是被动形式但错了.
C suggest sb.(should) do sth
是虚拟句
C 感觉应该是选它,首先last year,排除B D 后文中说but I don't know whether she has finished it
说明这个动作或许一直在进行,若选A 则表明动作已完成,而且动词ING 形式并非一定代表过去进行时,它还可以表示过去的连续动作.