pollute   million   use   but   we  keep   another   healthy   danger  of  other  with

The earth is our home; we must take care of it. This means that it is necessary and important 小题1:________the land, air and water clean. However, pollution is beginning to threaten(威胁) our小题2:__________, happiness and our life ——we see it, smell it taste it and discuss it.
Men began to小题3:________the earth a long time ago. When land was 小题4:________up or water became dirty, men had to move to 小题5:________places. At first, there weren’t so many people then and there were less trash. All the dirty things could be absorbed (吸收)by nature. 小题6:______now this is no longer true. The increase of population and the development 小题7:________ industry have changed that. Men are still polluting the environment.
later, 小题8:________of people have realized the小题9:________of pollution. A lot of people are now working hard to protec小题10:________ environment. Everyone should try their best to make our environment better and better.