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释义：“报名参加”，在留学文书里可以用来表示报了额外的课程、培训班或兴趣小组。

例句：
Among them is 13-year-old Ebony Green, an eighth-grader who decided to sign up for this extra science class to improve her academic record and her chances of finishing school and going to college.
Mrs. Macomb asking weepily why no one had signed up for her dancing club.