16. The cattle station in Australia is larger than that in Belgium. A. The cattle station in Belgium is not as large as that in Australia. B. The cattle station in Belgium is the largest in the world. C. The cattle station in Australia is the largest in the world. D. The cattle station in Belgium is as large as that in Australia. 17. If we don’t act soon, the pollution will get much worse. A. Unless the pollution doesn’t get much worse, we won’t act soon. B. Unless we act soon, the pollution will get much worse. C. Unless the pollution gets much worse, we won’t act soon. D. Unless we don’t act soon, the pollution will get much worse. 18. I don’t have enough money to buy that house. A. That house is cheap, so I can buy it. B. If I have enough money, I will buy that house. C. I should buy that house. D. If I had enough money, I would buy that house. 19. The police haven’t found the flood victims yet. A. The flood victims weren’t found by the police. B. The police can’t find the flood victims. C. The flood victims won’t be found by the police. D. The flood victims haven’t been found by the police yet. 20. If you don’t stop swimming in that lake, you will have a rash. A. Unless you don’t stop swimming in that lake, you will have a rash. B. Unless you stop swimming in that lake, you will have a rash. C. If you don’t keep swimming in that lake, you will have a rash. D. Unless you keep stop swimming in that lake, you will have a rash. 21. The polluted water results in the death of many aquatic animals and plants. A. The polluted water causes in the death of many aquatic animals and plants. B. The polluted water leads to the death of many aquatic animals and plants. C. The polluted water causes to the death of many aquatic animals and plants. D. The polluted water leads in the death of many aquatic animals and plants. 22. Australians use English as their mother tongue so they are native speakers. A. Australians are native speaker although they use English as their mother tongue. B. Australians are native speaker because they use English as their mother tongue. C. Australians are native speaker though they use English as their mother tongue. D. Australians are native speaker owing to they use English as their mother tongue.