Tom has to leave now he can catch the train.A. so thatB. as soon asC. becauseD. if

问题补充：

Tom has to leave now he can catch the train.

A. so that

B. as soon as

C. because

D. if

答案：

(答案→)A. so that

B. as soon as

C. because

D. if

解析：根据前后句的关系可知答案为A，引导的是结果状语从句。