Help yourself to __________.
--- Is this the first time you ___ Xiamen? --- No. But the first time I ____ here, the city wasn’t so beautiful.
_______ is known to us all that the old scientist, for _______ life was hard in the past, still works hard in his eighties.
The wounded soldier died _____I had a chance to know his name and family.
They came back from their long walk and went into bed, .
-----Must I go there right now? -----No, you _____. You ____go there before supper.A mustn’t , need B. needn’t, may C. can’t ,need D. won’t, can