It’s difficult _____ your sound because the noise is too high.
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.
The music is very wonderful, she often listens ___________.
These are the apples and bananas, cut ___________ and put ___________ the blender.