— the workers are very tired they keep on working. — They are great. We must learn from t

问题补充：

— the workers are very tired, they keep on working.

— They are great. We must learn from them.

A. Because; /

B. Though; /

C. Because; so

D. Though; but

答案：

A. Because; /

(答案→)B. Though; /

C. Because; so

D. Though; but

解析：句意：尽管工人们很累了，但他们仍然继续工作。——他们太伟大了，我们应该向他们学习。本题考查连词的用法。Because用于表示因果关系，不能与so同时使用；Though用于表示转折关系，不能与but同时使用。结合句意，故选B.