He didn’t go to school yesterday he was ill.A. becauseB. because ofC. ifD. so

问题补充：

He didn’t go to school yesterday he was ill.

A. because

B. because of

C. if

D. so

答案：

(答案→)A. because

B. because of

C. if

D. so

解析：本题的含义是昨天他没有去上学，他病了应该是他没上学的原因，because后跟原因从句，because of后跟单词或短语，故选A。