In summer, food will go bad if________in room temperature.
A policeman saw two thieves ____ a girl’s mobile phone on a bus and he caught them at once.
----Lily, keep the window ____. The sandstorm hasn’t stopped yet. ----OK, I’ll do that.
It was great fun _____ a picnic on the hill.
How long did you spend ____ your new house yesterday?
I’m thirsty. Will you get me something ____?