Mark the letter A, B, C or D to indicate the correct answer to each of the following questions. 8.Some of the collapsed buildings and houses____by the government so far. A.had repaired B.had been repaired C.have been repaired D.have repaired 9.______USA is the most diverse country in geography and climate. A.the B.a C.no article D.an 10.The_____\from the factory are dumped directly into the river next to the village. A.pollution B.pollute C.pollutants D.polluted 11.Sudden changes in water temperature may_____the deaths of aquatic animals and plants. A.result in B.lead in C.put out D.come up with