例句與用法

1. Since mankind appears on the earth , many inevitable problems occured : environment was polluted , fresh air was deteriorated and ecosystem became imbalanced
   由于人類的到來，地球上的一些問題就不可避免的產(chǎn)生：環(huán)境污染，空氣質(zhì)量惡化，生態(tài)失衡。 。 。