Mom had asked Jack to close the window before he went out he forgot to do it.A. Though;

问题补充：

Mom had asked Jack to close the window before he went out, he forgot to do it.

A. Though; /

B. Though; but

C. Till; /

D. Until; then

答案：

(答案→)A. Though; /

B. Though; but

C. Till; /

D. Until; then

解析：考查though的用法。句意“尽管妈妈让杰克出去前记得关窗户，但是他还是忘记了。”though不能与but连用。故选A。