We’ve just heard a warning on the radio a typhoon may be on its wayA. whatB. whenC. whic

问题补充：

We’ve just heard a warning on the radio a typhoon may be on its way．

A. what

B. when

C. which

D. that

答案：

A. what

B. when

C. which

(答案→)D. that

解析：考查同位语从句。同位语从句that a typhoon may be on its way对名词warning进行解释，说明该名词的内容。That在句中起引导作用，满意任何意思，不能省略。