The decorations were so lovely that they in a short time. A. sold outB. has been sold out

问题补充：

The decorations were so lovely that they in a short time.

A. sold out

B. has been sold out

C. were sold out

D. were selling out

答案：

A. sold out

B. has been sold out

(答案→)C. were sold out

D. were selling out

解析：考查时态和语态。句意：这些装饰品是如此地可爱，以至于他们很快就被卖完了。根据句意说明应该使用被动语态，根据前半句的were说明应该是一般过去时的被动语态，故C正确。