看看我这几句话的英语说法对不对

看看我这几句话的英语说法对不对
1,这样的现象是如何发生的呢?
Why this phenomenor is occured?
2,这种行为是很难保持的（前文说保护环境的个人行为往往意味着个人自己付出不便）
Such a behavior is hard to preserve.
3,确实,环境保护是现代社会最严峻的问题之一,我们需要用每一份可以利用的力量来解决它.
Certainly,environment problem is one of most serious challenge in modern society,we need to solve it by every possible power we can get.