他亲历了儿童时代的河流一步步被污染，鱼类一点点的消失。

He has seen the pristine river of his childhood become polluted and fish populations disappear.

youdao

他亲历了儿童时代的河流一步步被污染，鱼类一点点的消失。

He has seen the pristine river of his childhood become polluted and fish populations disappear.

youdao