Let's take a look at the following first. As pictured, this is my hands of a set of papers, all for single topic, the answer has been marked in the back of each question
The workaround is as follows:
1, use the shortcut key Ctrl+h, the replacement tool
2, in the "Find content" fill in the wildcard character "(^$)", to note that there are no spaces in parentheses, the two must match, in the "Replace with" to fill in "()", where the parentheses according to the document, to have a space
3, click Replace All, the following effect appears:
4, this method is most suitable for the processing of individual topics above, if it is multiple-choice, in the search to enter multiple "$"