一You’ve made great progress in your survey haven’t you?——Yes but some problems among the

问题补充：

一You’ve made great progress in your survey, haven’t you?

——Yes，but some problems among the youngsters still remain——．

A. settled

B. settling

C. to settle

D. to be settled

答案：

A. settled

B. settling

C. to settle

(答案→)D. to be settled

解析：可联系答.案.网客服索取。