Lungs are to human beings ___ the forest is to the earth.A.which B.what C.as D.it 选什么 为什么

Lungs are to human beings ___ the forest is to the earth.A.which B.what C.as D.it 选什么 为什么 Every few years,the coal workers （）their lungs X-rayed to ensure their health.A.are having B.have C.have had D.had had 英语翻译certain messenger molecules fight damage to the lungs from noxious air by telling the muscle cells encircling the lungs' airway to contract.This partially seals off the lungs.An asthma attack occurs when the messenger molecules are activa How do a human being's lungs work? Animals are ______great use to human beings A of B with Animals are ______great use to human beings A of B with ____useful robots are to human beings!A what a B how a C what D how Robots ___ some work of human .为什么选A?A.are used to do B.are used to doing human beings are human beings UFOs are supposed to be sent to___with the human beings.A.communicate B.speak C.contact D.touch说明理由 1.( ) he knows,he still needs to learna .as much b,though c much as d since2.-I'll be waiting for you at home .- ( ) I were busy and couldn't come?a .what if b .what when c how if d how when在加一题：Parks are to the city ( )lungs to the body． there are some troubles with my lungs这句话对么.. Human Connect To Human 歌词 Try not to cough more than you can_____since it may cause problems to your lungs.A．help B．allow C．stop D．check 23.Try not to cough more than you can ___ since it may cause problems to your lungs.A.check B.allow C.stop D.help 194.It is often _____ that human beings are naturallyequipped to speak.(全国II)A.said B.to say C.saying D.being said 6.It is often that human beings are naturally equipped to speak.A.said B.to say C.saying D.being said it is human activities on the earth that are to( ) global warming.Abe blame for B to blame for Ctake charge of Dbe responsible with