--I think it is necessary for everybody to take action _______ the Earth.--I agree. Turn off the lights before we leave the classroom.
—Where is Julie? —She is ________ in the supermarket.
—Hi,Jack!How’s it going? —________.We are having a great time in the water park.
Excuse me,sorry to trouble you.Can you please take a photo ________ us?
A group of people ________ playing basketball there.
Some of the water in the rivers ________ not clean.