3. If I had much money now, i would buy a house in PC
4.If light pollution happens, there will be a change in animals' living patterns
5.Trees' leaves are damaged because of dangerous acid rain
6.Tom is going to open another...
7.Phong has not visited Tasmania for five years
9.We haven't met for a long time
10.I haven't had such a delicious meal before
11.He hasn't gone abroad before
13. She hasn't talked to me for 5 months
19. Lights pollution makes us not to see...