Scientists said that air pollution was one of the causes of the greenhouse effect.

 The Nile the longest river in the world.

 Nam said that they could clean the beach together.

 South Korea is more formal in addressing their bosses than in America.

 Happiness and health are the most precious thing.

 Electronic devices whose radiation is very harmful are bad for your eyes.

 Electronic devices distract students who may play games, text chat, and cheat from the study.

 They told their son that they had seen a strange man in the garden.

 Emily said that they were staying in that night.

 He told his girlfriend that he had bought a ring. 

 She said that she had gone to work the previous day. 

 Bob apologizes for not coming to jane's birthday the previous Friday.

CHÚC CẬU HỌC TỐT!!!

4. scientists said that air pollution was one of the causes.... effect

5. the nile the longest river in the world

6. nam said that they could clean the beach together

7. the south korea are more formal in addressing their bosses than in the america

8. happiness and health are the most precious thing 

9. electronic devices whose radiation is very harmful are bad for your eyes

10. electrocnic devices distrac students who may play games, text chat and cheat from study 

11. they told their son that they had seen a strange man in the garden 

12. emily said that they were staying in that night 

13. he told his girlfriend that he had bought a ring 

14. she said that she had gone to work the previous day 

15. bob appologizes for not cming to jane's birthday the previous friday