Why can't I delete studying at school when I fill in the recruitment resume of Zhilian?

I just met this problem, and it will be fine after a while! !

Select "Please Select" for all the drop-down options, clear all other fields that need to be filled in, and then click Save, so that the message "* * * * not filled in" will not be prompted in red.

After clicking Save, the column "Studying at School" will become an "X" and will not appear in your resume.