问题
选择题
—Such a mistake could have been avoided.
—Unfortunately, he ________ the mistake again and again.
A．repeated
B．would repeat
C．had repeated
D．would have repeated
答案
答案：A
因为could have done是对过去发生的事表示遗憾，所以答语也应该是指他在过去一再犯这样的错误。