Question

he ( ) until twelve o'clock every night A stops working B stops to work C doesn't stop working

D didn't stop to working

Answer 1

C
解析：本句的意思是，他每天晚上都要工作到12点。
用not until句型（直到···才···），排除A.B
every night(每天晚上)，所以用一般现在时，排除D

关于stop短语：
stop to do sth. 停下来去做另一件事
stop doing sth. 停止正在做的事

呵呵。这是我自己做题的思路，希望对你有帮助。