Thank you.

1. you can use 3.47.20 and 3.48-9 update url:

<Http://www.tmjzzx.com/about.asp>

And compare the local file before update and after ,the local webpage did not
change .

But,

the 3.47.20 does not Update local file,

the 3.48-9 will always update the local file.

This creates an idea:

HTTrack maybe compare the first and the second from the server has to browse
the results are different, namely local file update is different before and
after, to identify whether the file changes. Not to the server to send
information to judge whether the different two.

2. Below url:

<Http://www.tmjzzx.com/shownews.asp?News_id=1359>

The 3.47.20 and 3.48-9 updates webpage, each will update the local file.

And compare the local file before update and after, content is changed, the
number of times webpage viewed changed, other content did not change.

This produces another idea:

HTTrack maybe set the webpage content to ignore the keyword:

When the ignore keyword changes, other contents did not change, don't think
the webpage has changed - not update the local file;

When other content outside ignore keyword changes, that the webpage has
changed - update the local file.

Above, for reference only.