He came to my class every week, but his attitude ________ he was not really interested in the subject

Even if you are in rush, pushing someone so that you can get into an elevator (电梯) is just bad manners.

The teacher told the students any food into the computer room.

He seems to be a teacher.—______. He has been a teacher for 20 years.

You wil find what great benefit the computer you own can be____ each time you use it to help you work