Your cousin is said a new puter program recently, but do you know when he will finish it?
A. to design
B. to be designing
C. to have been designing
D. to have designed
网友回答
A. to design
B. to be designing
(答案→)C. to have been designing
D. to have designed
解析：考查固定结构的含义sb/sth+be+said/reported/thought(过去分词)+to do/to be doing/to have done, 具体意思为：to do 表将来；to be doing表示正在进行；to have been doing表示从过去一直在进行到现在，并且现在还在进行；to have done表示动作已经结束，发生在谓动词之前。句意为：据说你的堂兄最近在设计一种新的电脑程序，但是你知道他在什么时候完成吗？从句意中可知，他设计了一段时间，但还没有完成，应在进行中，故应使用to have been doing的形式，答案应为C。