Question

Simon thought his computer was broken _______ his little brother pointed out that he had forgotten to turn it on

1. A.
   until
2. B.
   since
3. C.
   after
4. D.
   because

Answer 1

A
解析：
本题考查连词。根据句意他一直以为电脑坏了，直到他弟弟告诉他忘记开机了；
not...until...意为“直到……才”。