. It is clear that the whole world is passing through a social revolution in which a central _____ must be taken by scientists and technologists.
--Oh, must you? Stay a longer. It's been such fun having you--__________. I've got an early start tomorrow morning.
Beijing government puts more than 700 million yuan to increase its green space this year; ____________ doubles the money provided last year.
I can guess you___________ your sweater inside out.
It is only when you nearly lose someone ____________ you fully realize how much you value him.
--I'm going downtown. --Come on. __________.