19. --- Could you tell me how the sea sand comes about ? --- Sea waves dash against the rock. In this way , the sea sand ___ .
We’ll not attend the meeting _____ we are invited.
This is the second time that he ____________ China.
I offered my ____________John ______ winning the sports.
-- A good book is a good friend. You can get the help you need from it. ----- You said it. ___________.
_____ of the students who took part in the military training is 450.