In order to get good marks in the coming exam, my son ______late every night in the past three weeks.
If you want to study in foreign countries, ____ good knowledge of the culture is regarded as ____ must for you to live happily.
-How would you like your coffee? -____.
As we all know, water ______ hydrogen and oxygen.
When _____ help, one often says “Thank you.” or “it’s kind of you”
He narrowly escaped _______ by the falling tree.