When I play Warcraft 3 against the human computer, I find that sometimes the computer doesn't upgrade its base. For example, this time it got stuck at level 2 base.

The reason is that the computer will expand and place two towers around the secondary base. If both of these towers are upgraded into arrow towers, the humans will stop upgrading the base.

At this point, you need to send troops over to destroy its tower so it can rebuild.

After that, it built an arrow tower and a magic-sucking tower.

Then it started upgrading the base normally