Children above 12 are able to take part in skiing or other activities for them.A. designed

问题补充：

Children above 12 are able to take part in skiing or other activities for them.

A. designed

B. designing

C. to design

D. having designed

答案：

(答案→)A. designed

B. designing

C. to design

D. having designed

解析：考查分词做定语。本题的design与名词other activities构成被动的关系，故使用过去分词的形式，做定语修饰名词other activities。句意：12岁以上的孩子能够参加滑雪孩子其它的为他们设计的运动项目。故A正确。