Because the shop all the T-shirts are sold at half price.A. has closed down B. closed do

问题补充：

Because the shop , all the T-shirts are sold at half price.

A. has closed down

B. closed down

C. is closing down

D. had closed down

答案：

A. has closed down

B. closed down

(答案→)C. is closing down

D. had closed down

解析：本题考查动词时态，根据语境主句为一般现在时，首先可以排除B和D选项，B和D分别为一般过去时和过去完成时，前后时态不一致，另外A是现在完成时表示商店已经倒闭，根据句意“因为商店将要倒闭，所以所有体恤衫现在半价出售”。C项在这里用现在进行时表将来。故选C。