Im pleased to see the problem so quickly.A. settledB. having been settledC. be settledD.

问题补充：

Im pleased to see the problem so quickly.

A. settled

B. having been settled

C. be settled

D. settle

答案：

(答案→)A. settled

B. having been settled

C. be settled

D. settle

解析：see sth. done表示“看见某事被完成”。