The radiation amount of a mobile phone for two half-hour periods per day is equal to ___ to an X-ray for ten seconds.
What surprised me was not what he said but ______ he said it.
— ______ will get the first prize? — I'm sure, Li Hua.
_____ leaves the room last ought to turn off the lights.
Why not seize it _______ you’ve got such a good chance?
You can’t imagine ______ when they received these nice Christmas presents.