to sign up for选课
sign up for inform探询
sign up for报名参加;选课;登记报名
Sign up for conferences报名参加会议;为会议;为会议签署;注册为会议
sign up for training报名参加培训
sign language for education教学手语
Sign up for a申请一个吧
Sign convention for torque扭矩符号的规定
Sign Up for Newsletter登记邮件列表
PHRASAL VERB（动词词组） If you sign for something, you officially state that you have received it, by signing a form or book. 签收
When the letter carrier delivers your order, check the box before signing for it.
当那个邮递员将你订购的货物送到时，签收之前检查那个包装盒。