---Is it Pro. King that will give the lecture on radiation?--- I can't I know it for sure

问题补充：

---Is it Pro. King that will give the lecture on radiation?

--- I can I know it for sure.

A. say

B. tell

C. speak

D. talk

答案：

(答案→)A. say

B. tell

C. speak

D. talk

解析：考一组动词同义词的区别。意思是“我不敢说我对此事十分清楚。”say后要跟所说的内容。tell的固定用法为tell sb about sth，tell a story，tell a lie，tell the truth；而speak则是speak to sb, speak at a meeting, speak English; talk的通常用法为talk to/with sb；talk about sth。