30. If Trang _______ her room every day, her mother _______ so upset. A. tided/ wouldn’t be ​C. tidies/isn’t B. tides/ won’t be ​D. tided/ won’t be 31. May aquatic animals die ________ the polluted water. A. because ​B. due to ​C. because of ​D. Both B&C 32. The cold weather in this country often makes him ________. A. sneezing ​B. sneeze ​C. to sneeze ​D. sneezed 33. _______ there was a lot of acid rain, many botanical species died last year. A. Since ​B. Cause ​C. Although ​D. So 34. We ________ pay so much money for electricity a month if we ________ the air conditioner all the time. A. wouldn’t have to/ don’t turn on ​C. wouldn’t had to/ didn’t turn on B. would have to/ didn’t turn on ​D. wouldn’t have to/ didn’t turn on 35. If the villagers didn’t dump households waste into the river, it _______ less contaminated now. A. will be ​B. is ​C. could be ​D. being 36. If Hoa ________ ill, she would join our activity to protect the local environment. A. wasn’t ​B. weren’t ​C. isn’t ​D. Both A&B