求翻译：由于一些学生在校园里乱扔垃圾，在墙上乱画，不注意校园的环境，使我们的环境有了很大的改变，现在很少有蝴蝶和鸟儿来唱歌，环境也没有以前干净是什么意思？

Because some students on campus littering, graffiti on the wall, pay attention to the campus environment in which our environment has changed dramatically, and now very few butterflies and birds to sing, a clean environment not previously

Due to some students on the campus, litter on the wall paintings and campus environment, do not pay attention to our environment, there was a significant change, it is now very rare butterflies and birds singing, the environment and no previous clean

Because some students throw trash in the campus, doodles on the wall, does not pay attention to the campus the environment, enable our environment to have the very big change, now very little has the butterfly and the bird sings, the environment also did not have before was clean

Litter because some students in campus, doodling on the walls without attention to campus environments, make our environment has greatly changed now little has butterflies and birds singing, environments and no previous clean

Because some students on campus littering, graffiti on the wall, pay attention to the campus environment in which our environment has changed dramatically, and now very few butterflies and birds to sing, a clean environment not previously