几道英语选择题,怎么选?说出道理.thanks!^-^

几道英语选择题,怎么选?说出道理.thanks!^-^1.Hurry up!The train_______.you know it ____at 8:30 am.A.leaves;leaves B.is leaving;leaves C.leaves;is leaving D.is leaving;is leaving2.-----Anny,you____ books about.look,what a mess in your study!-----Sorry,Mum.I won't do that again.A.have always thrown B.always throw C.are always throwing Dalways threw3.The teather,along with his students,_____on the ground in the setting sun.A.play B.playing C.is playing D.are playing4.I don't really work here;I___ until the new secretary arrives.A.just help out B.have just helped out C.am just helping out D.will just help ou5.----You've left the light on.----Oh,so I have._____and turn it off.A.I'll go B.I've gone C.I go D.I'm going to6.The time______,so let's hurry up.A.has run out B.is running out C.has been run out D.is being run ou