He would feel pressured when _____ to answer the teacher’s questions in class.
The trees ____ front of the house are ____ the charge of Old Li.
- Do you go there ____ bus? - No, we go there ____ a train.
In Hangzhou Mr Green was so struck ____ the beauty of nature that he stayed ____ another night.
He is running ____ the wind towards the east of the station ____ Tom is running ____ the right.
I don't think you can work out the maths problem ____ the teacher's help.