callon

1.指名要(某人)去干(某事);请求,要求;号召

2.访问

1.to officially ask a person or organization to do something

2.if a teacher calls on a student, they ask them to answer a question

3.to decide to use something that someone can offer you

4.to produce a particular quality in yourself, especially by making a great effort

5.to ask someone to prove a statement they have made

6.to visit someone, usually for a short time