where to edit "thoughts on " xxx i want change the word?

Just below the box where you typed this is, it says

Did you include a link to your site, so that others can see the problem?

Do that, and tell us which theme you are using and if you are using a child theme.

https://www.nyc886.com/2014/06/%E6%88%91%E7%9A%84%E6%8E%A8%E5%B9%BF%E6%96%B9%E5%BC%8F/#more-96

i use twenty twelve

start by creating a child theme of Twenty Twelve;
https://codex.www.ads-software.com/Child_Themes

then save a copy of comments.php into the child theme (for instance per FTP)

then edit comments.php;

the text is near the top:

printf( _n( 'One thought on “%2$s”', '%1$s thoughts on “%2$s”', get_comments_number(), 'twentytwelve' ),

thanks