Seeing the policeman, the thief was behaving __________ nothing had happened

It’s surprising that your brother ________Russian so quickly—he hasn’t lived there very long.

Our boss is very glad because our company has _____ all its goals this year.

I ________ use a clock to wake me up because at six o’clock each morning the train comes by my house.

The missing boys were last seen ______ near the river.[ ]