-There is no doubt he will come tomorrow.---But I doubt he will come here on time.A.

问题补充：

---There is no doubt he will come tomorrow.

---But I doubt he will come here on time.

A. that; that

B. if; that

C. whether; that

D. that; if

答案：

A. that; that

B. if; that

C. whether; that

(答案→)D. that; if

解析：句意：毫无疑问他明天回来。但是我怀疑他是否会按时到这。There is no doubt that. ........是毫无疑问的。if/whether 是否。