is no doubt John’s knowledge of first aid saved Ms Slade’s life.A. It; thatB. It; which

问题补充：

is no doubt John’s knowledge of first aid saved Ms Slade’s life.

A. It; that

B. It; which

C. There; that

D. What; that

答案：

A. It; that

B. It; which

(答案→)C. There; that

D. What; that

解析：there is no doubt that是固定用法，意思是某事毫无疑问。