PS:请写出为什么1.Please make sure that the light ___ off before you leave the room.A.will turn B.will be turned C.is turned D.turns2.I will try my best to finish it ____ it may mean to me.A.however B.whenever C.wichever D.whatever

1.选C.is turned
Please make sure that the light is turned off before you leave the room.
【is turned off这里是一般现在时表示一种状态,句意是：请确保在离开教室前那个灯是关着的.（言下之意就是请在离开教室前把灯关上,并确认一下它是“关着”的这状态.】
常见的还有Please make sure that the door is locked before you leave the room.请在离开教室前确保门已经锁上,也是用is locked来表示一种状态.
2.选D.whatever
I will try my best to finish it whatever it may mean to me.无论这对于我来说将意味着什么,我都会尽力去完成的.
however=no matter how 无论怎样
whenever=no matter when无论何时
whichever=no matter which 无论哪一个
whatever=no matter what无论什么
根据句意可知,应该是 no matter what it may mean to me,也就是whatever it may mean to me 无论那对于我来说是什么,无论那将意味着什么