Tom didn’t go hiking with his classmates his illness.A. because B. because of C. since

问题补充：

Tom didn’t go hiking with his classmates his illness.

A. because B. because of C. since

答案：

解析：句意:因为生病Tom没有和他的同学们一起去徒步旅行。because 是一个连词，后面引导原因状语从句，这个空的后面是一个名词，故它不对；because of 是一个短语，后面根名词或动词的ing形式，故符合句意；since 可以表示原因，也是来引导原因状语从句的。故选B。