—It’s reported that more than 20 people have died of H7N9 so far.— .
What did you buy during your last vacation? I __________ a hat.
--- ___________ there any sharks in the aquarium? --- No, we didn’t see any.
It’s not good for people __________ waste water (污水) into the river.
Every student in Miss Chen’s takes turns __________ the classroom every day.
Please tell your partner _____________ make your favorite smoothie.