13. These flowers often grow on river ________ and near streams.
A. stop B. place C. bank D. wall
14. If factories pump their raw ________ into the sea, many fish will die out.
A. water B. trash C. sewage D. spill
15. The ________ of electricity always increases in hot water.
A. consume B. consumption C. consumes D. consumed
16. Because of the outbreak of COVID-19, the course has been shortened ________.
A. consider B. considerable C. considerably D. considering