Mr. White had no money for the taxi, so he had to ______ home.
---I seem to be lost. Could you tell me _____? ---Sure. You can take the No.3 bus to get there.
--- What did Mike say? ---- He said ______.
Tom asked my friend ________.
It is clever ______ you ______ out the problem.
_____________ is necessary __________ he trains himself before the Guangzhou Marathon.