几个英语选择题.1.what would it be like to travel at the speed of --

几个英语选择题.1.what would it be like to travel at the speed of ____?CA.a light B lightsC.light D an light这里的light什么意思?2.if he had worked harder,he____________________DA.would succeed B had succeeddeC,should succeed D.would have succeededwhy?3.this is the first time i ___________here.BA.was B have beenC.came D.am coming不应该是C吗4.he has spent a ___________ day.CA more worry B most worryingC more worrying D most worry5.you _____________ to the meeting this afternoon if you have something to do.DA,needn't to comeB.don't need comeC,don't need comingD.needn't come区别用法什么的