The doctors and nurses were very tired they still went on working.A. soB. andC. orD. but

问题补充：

The doctors and nurses were very tired, they still went on working.

A. so

B. and

C. or

D. but

答案：

A. so

B. and

C. or

(答案→)D. but

解析：此题考查连词so，and，or和but的区别。So表示因此，所以；and表示和，而且；or表示或者，否则；but意思是但是表示转折。本句的含义是虽然医生和护士都非常劳累，但他们仍然继续工作。根据语境可知应选择D。