---Is it Pro. King that will give the lecture on radiation?
--- I can't I know it for sure.
A. say
B. tell
C. speak
D. talk
网友回答
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。