Question

【题目】Kangkang went to Beijing International school when he was twelve.(改为同义句）
Kangkang went to Beijing International school twelve.

Answer 1

【答案】at；the；age；of
【解析】句意：康康12岁的时候去了北京国际学校。表达年龄的短语：at the age of在……岁时。所以答案是at the age of。