Definition
- C1
to request someone formally to perform a task or action
动员；呼吁；邀请
The teacher called on the students to answer questions during the class.
老师在课堂上请学生回答问题。
We need to call on the experts to share their insights at the upcoming meeting.
我们需要邀请专家在即将举行的会议上分享他们的见解。
At such a critical moment, I decided to call on my friend for help, especially because I needed his expertise.
在如此关键的时刻，我决定向我的朋友求助，特别是因为我需要他的专业知识。