“Things________never come again！” I couldn’t help talking to myself.

—Can those________at the back of the classroom hear me?
—No problem.

You need some facts _____ to base your theory.

________ for not keeping his promise，Gary hung his head in shame.

It was ______ the president's speech that the secretary spent the whole morning at home.

Sarah pretended to be cheerful,            nothing about the argument.

________ in a red dress, she was easy to _______ in the big crowd.

Sometimes I’m dying ______ him about it.

Rare species in the world, ______ by hundreds every year, must be jointly preserved by all countries, or humans will encounter ecological disaster in the near future.

He is used to        to his office in spite of bad weather.