1 When pollutants are not removed from sewage and are discharged into the river. 

2 We need fresh water for drinking, cooking and washing. Animals living near the river, as well as fishes and aquatic plants, also depend on clean river water.

3 Pollutants accumulated within the boundaries of the catchment area may be washed into river channels.

4 Through our drainage systems 

5  Industrial waste may contain sulfur, resulting in increasing the acidity of the river water. 

If the water weren't too dirty, we could bathe in this part of river.

If the water weren't too dirty, we could bathe in this part of river.

Rivers are on of the world’s most important natural resources. Many cities are on the large rivers, and ……almost…….. every country has a least one river that …plays…….. an important part in the lives of its people. Besides transportation, river.......provide……………..water for crops, water to drink , and recreation for people who live along their ……banks…….. And in ……order…….to get water for crops, engineers sometimes build a dam…across………a river and let water become a lake behind the dam. Then people can use their water not……only…..to irrigate fields but also to make electricity for homes and industries. ……However…….the water often becomes polluted when cities on river bank grow up and the number of industries increases. We are learning that it is necessary to ……keep……rivers clean if we want to enjoy the benefits of the natural resources.

Rivers are on of the world’s most important natural resources. Many cities are on the large rivers, and……almost…….. every country has a least one river that …plays…….. an important part in the lives of its people. Besides transportation, rivers …provide……………..water for crops, water to drink , and recreation for people who live along their ……banks…….. And in ……order…….to get water for crops, engineers sometimes build a dam …across………a river and let water become a lake behind the dam. Then people can use their water not ……only………..to irrigate fields but also to make electricity for homes and industries. ……However…….the water often becomes polluted when cities on river bank grow……in……….size and the number of industries increases. We are learning that it is necessary to……keep……rivers clean if we want to enjoy the benefits of the natural resources.

from ; means ; in ; waste ; possible ; wind ; should ; green ; However ; who

Much of our waste, especially waste ..from..... factories, electric-powered stations, the chemical industry and heavy industry is very dangerous. Fish die ..in... the lakes, rivers and seas; forest trees die, too. Much of this dangerous .waste..... goes into the air and is carried by the ...wind.... for great distances.

The earth is our home. We ....should... take care of it, for ourselves, and for our children and grandchildren. This ...means.... we have to keep our environment ..green... and clean . The importance of this task is pointed out by ecologists - the scientists ...who.... study the relations between living things and the environment. ...However..., each of us must do everything ..possible.... to keep the land, air and water clean.

from ; means ; in ; waste ; possible ; wind ; should ; green ; However ; who

The earth is our home. We ....SHOULD.. take care of it, for ourselves, and for our children and grandchildren. This ....WASTE... we have to keep our environment ..GREEN... and clean . The importance of this task is pointed out by ecologists - the scientists ...WHO.... study the relations between living things and the environment. ...HOWEVER..., each of us must do everything .....POSSIBLE. to keep the land, air and water clean.

1. I am a member of the anti-pollution program in my school. I often go to school by bus (so)

=> I am a member of the anti-pollution program in my school so I often go to school by bus.
2. The street in this area were cleaned off. Public facilities would be constructed.(because of)

=> Public facilities would be constructed because of having cleaned off the streets in this area.
3. Fresh, clean water is very important to life. No one can live long without it (since)

=> Fresh, clean water is very important to life since no one can live long without it.
4. Kim never cleans her room. Her mother is complaining (because)

=> Kim’s mother is complaining because she never cleans her room.
5. Many aquatic animals are dead. The water is polluted (due to)

=> Many aquatic animals are dead because of water pollution.

If the water weren't too dirty, we could bathe in this part of river.

We can't bathe in this part of river because the water is too dirty.

If....the water isn't too dirty , we could bathe in this part of river..

1. The air in the city is very polluted .(pollute)

2. We'll make this beach clean and beautiful again . (beauty)

3. If the pollution continues , what will happen ? (continue)

4. The world's population is growing quickly (quick)

5. If doesn't rain soon , there'll be a great shortage of water . ( short)

I . Give the correct form of the works given to complete the sentences :

1. The air in the city is very ......polluted....................(pollute)

2. We'll make this beach clean and .........beautiful............again . (beauty)

3. If the pollution .......continues.............., what will happen ? (continue)

4. The world's population is growing ...........quickly..........(quick)

5. If doesn't rain soon , there'll be a great ..............shorts................of water . ( short)

I . Give the correct form of the works given to complete the sentences :

1. The air in the city is very polluted (pollute)

2. We'll make this beach clean and beautiful again . (beauty)

3. If the pollution continues, what will happen ? (continue)

4. The world's population is growing quickly (quick)

5. If doesn't rain soon , there'll be a great shortage of water . ( short)

Chúc bạn học tốt!!@^^@!!

Selina lives in a village in Africa .Her day works 4o'clock.She gets up and she walks three kilometers to the river .She collects some water ,and she carriesm it back to her house .The water is very heavy.It isn't clean but there isn't any water in the village.Selina doesn't go to school.She can't read or write.She helps mother in the house.

1.Where does Selina live?

=>Selina lives in a village in Africa.

2.What does Selina do after she gets up?

=>After Selina gets up,she walks three kilometers to the river to collect some water.

3.Is the water clean?

=>No,it isn't.

4.Can she read?

=>No,she can't.

5.Where does Selina help her mother?

=>Selina helps her mother in her house.

6.What does she collect?

=>She collects some water.