She had to drop out of school her family couldn’t afford the cost of her education. A. al

问题补充：

She had to drop out of school her family couldn’t afford the cost of her education.

A. although

B. unless

C. because

D. so

答案：

A. although

B. unless

(答案→)C. because

D. so

解析：连词辨析。A尽管；B除非,如果…不…;C因为；D于是；句意：因为家里承担不起教育的费用，他不得不辍学了。根据句意说明上下文是因果关系，横线后面表示的是愿意，故使用because。故C正确。