--- one and a half months enough for the project to be finished?
---I am afraid not. The professor is ill and only after he recovers go on with it.
A. Is; he can
B. Are; he can
C. Is; can he
D. Are; can he
网友回答
A. Is; he can
B. Are; he can
(答案→)C. Is; can he
D. Are; can he
解析：句意：这个项目完成一个半月足够了吗？--恐怕不能。教授生病了，只有他恢复了才能继续。第一空需要be动词，主语是one and a half months表示一段时间，谓语用单数，所以排除BD，第二句话是only+时间状语从句在句首，后面用部分倒装，can放在主语前面，所以选C。