Question

Don't turn on thr computer until you_________ A were allowed

Answer 1

=Don't turn on the computer until you are allowed to turn it on.

先说时态：应该用一般现在时表将来.

allowed to后面省略了不定式（不定式是主语补语）.如果选D,allowed后就不清楚是什么了.

又如：

I wanted to go out but my mother told me not to (go out).