5. The sea is polluted, which _________ sea plants and animals. A. dangers B. dangerous C. dangerously D.endangers 6. _________means “a state of being polluted”. A.contamination B. cleaninese C.harm D.threat 7. Sperm whale population is ________ risk due to hunting. A.in B.at C. on D.of 8. ________means “the movement of something around a closed system”. A.elimimate B.run-off C.circulation D.hydroelectric 9. Let’s ________to the cinema. A.goes B.go C.to go D.going 10.When they came, the meeting________. A.start B.started C.had started D.is starting