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：
本題考查連詞。根據句意他一直以為電腦壞了，直到他弟弟告訴他忘記開機了；
not...until...意為“直到……才”。