单选题：_____ you have heard the song, you'll never forget it. [ ]..

They didn't discover until they happened to enter the back room ______ someone had stolen the priceless painting.A. that B. what C. which D. when

Harry is feeling uncomfortable.He________too much at the party last night.A．could drinkB．should drinkC．would have drunkD．must have drunk

I saw his mother ______ him down on the bed and he _____ there quietly. But I never knew hismother was ______ to me when saying he was dying.A. lay; lied; lying B. laid; lay; lying C. lain; lay; lieing D. laid; lied; lieing

_____ Tom has no interest in piano, there is no point pushing him to learn it.A. In case B. Now that C. Even if D. As far as

Please tell him it is time for the meeting and _____ all the workers are waiting.A. thatB. whatC. /D. where