C. came

16. concerns
17. effects
18. feelings
19. wishes
20. decisions
21. It is for the college that dating is left in Japan.
22. Is is girls that are to buy boys white chocolate on valentine's Day in Japan.
23. It is a South Korean boy's girlfriend's handbag that the boy often holds during a date.
24. It was a more traditional woman that once married, the South Korean man expects his wife. 

1. COal will be used to heat their house.
2. Many people will be attracted by this well-known historical site.
3. My bike will be repaired.
4. Umbrellas and raincoats will be left in the cloakroom.
5. Advertisements on TV will be banned.
6. Solar energy will be used by many countries in the future.

7. Wind and solar power will be used to solve the problem of energy shortages.

8. A great deal of energy will be generated by nuclear and hydro power in the future.

9. A campaign will be launched for using renewable energy by the government next month.

10. The tax will be increased on petrol next year.

1. in
2. has
3. eyes
4. is
5. hair
6. grows
.
1. teacher
2. school
3. friend
4. competition
5. watches
6. reads
7. stays up
8. bed
.
1. C
2. A
3. B
4. D
5. B
6. C.

`1/2 x + 2/3 (x-1) = 1/3`

`1/2 x + 2/3 x - 2/3 = 1/3`

`(1/2 + 2/3) .x = 1/3 + 2/3`

`7/6 x=1`

`x=1 : 7/6`

`x=6/7`

`2x(x+3)-x(2x-1)=2x^2+6x-2x^2+x=(2x^2-2x^2)+(6x+x)=7x`

5. their -> its