Giúp mik chọn đáp án nhanh chỉ cần A,B,C hoặc D thôi ạ IV. Choose the best answer (A, B, C or D) 21.What is the main ……… of visual pollution? - Because there are too many advertising billboards. A. effect B. affect C. result D. cause 22.By 1970, Canada …………… to choose the maple tree with the leaves as its national icon. A. decided B. has decided C. had decided D. have decided 23.If an earthquake suddenly …………… now, what …………… you do? A. would occur – would B. occurred – would C. will occur - will D. occurs - will 24.The victims of the wildfire …………… to the hospital already. A. has been taken B. have been taken C. has taken D. have taken 25.If the factory…… dumping poison into the lake, all the fish and other aquatic animals ……… A. continued - will die B. continues - will die C. continues - die D. continued – died 26.All the windows of my house…………… in the last night’s storm. A. broke B. had broken C. were broken D. had been broken 27. Air pollution has many effects …………. the environment and living organisms. A. in B. of C. for D. on 28. The volcano has erupted approximately once every ten years_________ 1970. A. since B. in C. from D. for 29.If I ……… a millionaire now, I ………… travel around the world. But in fact, I have only a little of money. A. am-will B. am-shall c. was-will D. were-would 30.The kangaroo has been known as a symbol of Australia …………… 1773. A. since B. from C. for D. in 31. ………. plastic takes so long to break down, it pollutes the land and water. A. Even though B. While C. Since D. Because of 32. If I had the chance to take part in an International summer camp, I ………… very excited. A. am B. was C. will be D. would be 33. …………. do earthquakes usually last? - Less than one minute. A. How strong B. How long C. How often D. How far 34. Niagara Falls is a great natural ………… on the border of the USA and Canada. A. castle B. loch C. spectacle D. symbol 35. The 2010 Haiti earthquake was the most …… natural disaster in the history of this country. A. destructive B. permanent C. unique D. awesome 36. “A hurricane is heading toward our home town.” - “……………..” A. That’s a relied. B. How interesting! C. Glad to hear. D. Oh my Go