----Do you know_____ second-hand smoke? ----To prevent our health and memory.
Boys, don’t lose____ in playing Angry Birds. It is bad for your eyes to play computer games for a long time.
—What do you want to be in the future, Lucy?—I want to be _____ pilot. It is _____exciting job.
New technology____________to stop the students from cheating in the exam last year.A. is used B. used C. was used
--Why are the windows so dirty?--Because we_________them for a long time.A. have cleaned B. haven't cleaned C. didn't clean
Mr. Wang often encourages us_______close to nature and enjoy its beautiesA. get B. getting C. to get