—Has anyone taught him how to do it?—Sure. Lots of advice________, but he hasn’t made a decision.
________ under the tree? No,they aren’t.
The baseball is _____ the floor _____ the desk.
--____________? --No, it isn’t.
--What are these? --_______ books.
如果你想知道对方姓什么时,你应该问_____________________________