Most environmental problems exist because adequate measures for preventing them___taken in the past.A.was not B.were not C.were not being D.being not 请说明原因,

environmental environmental environmental Most environmental problems?Most environmental problems exist because adequate for preventing them…taken in the past.…were not,were not being,had not been.选什么?其它怎么不对? environmental aerosol environmental是什么意思 英语翻译An environmental service is a sector where most trade take place through commercial presence with the accompanying presence of natural persons. Most environmental problems exist because adequate measures for preventing them_____taken in the paA、was notB、were not beingC、were notD、being not 独立主格Among the most dangerous environmental threats that we face ARE compu-garbage,Are哪里错了?为什么改,改成什么? 英语口语考试,求speechTopic 1:Environment IssuesDirections:You are talking about environmental problems that worry you most as well as how to act green in daily life. an environmental problem in environmental friendly material是什么意思 high environmental 怎么翻译 Environmental workers怎么读 environmental damage是什么意思 ENVIRONMENTAL意思是什么? the goldman environmental foundation environmental matrices是什么意思