Dựa vào từ cho sẵn viết câu hoàn chỉnh

Dựa vào từ cho sẵn vt câu hoàn chỉnh 
1. if/people/not/stop/dumping/waste/into/rivers/,/pollution/increase/.
2.if/polar/ice caps/melt/,/hugelandmasses/be/under/water.
3.if the air/in/city/be/polluted/,it/can/cause/people's/respiratory/problems.
4.if/smog/be/frequently/formed/in/city/,/it/cause/dificulty/in/breathing/headache/even/lung cancer.
5.if/carbon monoxide/concentrate/in/great/amounts/,/it/be/harmful/.
6.the climate/change/if/more trees/be/cut/down/for/hardwood/.
7.if/we/not/contro/pollution/soon/,/it/be/too/late/.
8.if/we/not/protect/frontier/,/we/suffer/many/from/natural/disasters.