It is time that authorities concerned took proper steps to solve the traffic problems.
问题描述：
It is time that authorities concerned took proper steps to solve the traffic problems.
上面一句话中的concern 为什么加ed啊,我不太明白.
那这句话的后面为什么用took啊
答
这里是分词做定语,修饰authorities.意思是：有关当局.因为是做定语,修饰成分,所以应该用分词形式.concerned表示“有关的” concerned只是修饰“authorities”的,对句子其它部分没有影响.至于took,这是一个固定用法：...