I need a bike __________ to school.
There are ______ flowers in the square during the National Day.
---How do you learn English? ---I learn watching English videos.
---Did you get there by ______ bike? ---No, I took ______ taxi.
—Would you like to go out for a walk with us?— ,but I must finish my homework first.
I usually sleep with the window open _____ it’s very cold.