Newton was playing under an apple tree ____ an apple fell onto his head.

What time do you usually get up — _____.

A good story does not necessarily have to have a happy ending，but the reader must not be left ________.

He’s still not understood by his close friend although he has said sorry to him； ______

The meaning of a word can be guessed according to the context, so you will not ______ refer to adictionary the next time _______ you come across a new word [ ]