The waste water, when _______,should be clean enough to meet standards.
(2012全国新课程)I use a clock to wake me up because at six o'clock each morning the train comes by my house.
I’m going to Europe on vacation together with John if I _______ find the money.
Don’t handle the vase as if it ____ made of steel.
We ______ the difficulty together, but why didn’t you tell me?
I______ thank you too much for all your help to my son while we were away from home.