He sat----against the wall and listened to the teacher-----

D close做副词有两种用法
1.接近,靠近地[(+to)]
They live close to the museum.
他们住在靠近博物馆的地方.
2.紧密地,紧紧地
Anna followed close behind.
安娜紧随在后.
closely 做副词有以下用法
副词 ad.
1.接近地
He resembles his father very closely.
他非常像他的父亲.
2.紧密地
Good teaching and good testing are closely related.
出色的教学工作与完善的测试制度密切相关.
3.亲近地,亲密地
They are closely related.
他们是近亲.
4.严密地,仔细地
The prisoners were closely guarded.
囚犯受到严密监视.
5.节省地;吝啬地