These new types of energy cost very little and will never ______．（ ）
A．look outB．come outC．run outD．stay out
Lucy，when you leave the room，please ____the light．
OK，Mom．（ ）
A．put offB．turn offC．turn up
____my grandpa is over 80 years old， he still looks strong and healthy．（ ）
A．AlthoughB．BecauseC．Unless
Be more____next time， and you won't make the same mistake again．（ ）
A．carelessB．carefulC．nervous
This is a really old bike．
Yes，I____it for seven years．（ ）
A．have hadB．have bought
C．Bought
How is your friend going to the station？
I'm not sure． He____take a taxi there．（ ）
A．mustB．has toC．may