Once harm is _______ to the eco-system,all species will ________,including man himself.A.made; be in danger B.done; be dangerous C.caused; be endangered D.done; be in danger

Once harm is _______ to the eco-system,all species will ________,including man himself.A.made; be in danger B.done; be dangerous C.caused; be endangered D.done; be in danger Watching TV too much is _______（harm）to our eyes. once harm is done to the environment,it takes years to have the system _A recoverB recoveringC recoveredD to recover Once harm is done to the environment,it takes years to have the system recovered.这是什么从句?哪是从句,哪是主句? Playing computer games is delightful, but _______ (spend) too much time on it may do harm.用动词的适当形式填空 The water in the river is (harm) Drinking polluted _water the healthA do harm to B does harm to C is harmful for B does harm to Drinking too much your health.A.do harm to B.is harmful C.does harm to D.do harm There is no harm in trying.There is no harm in trying.in trying是什么语法? Once harm ( )to the environment,it takes years to have the system recovered 括号里填什么,为什么A.does B.is done C.will be done D.be done once is enough 歌词 Tell me the trick _______ once pollution is (harm) to 中间用什么形式 what possible harm is smoking likely to do? lt is known that smoking does great ----[harm]to us. waste gas is _____(harm) to the environment Once environmental damage _______,it takes many years for the system to reca、has done b、is to doc、 does d、is done Drinking too much ____your health A do harm to B is harm to C does harm to D do harmful to