H:\myphp_www\PHPTutorial\WWW\tpblog>composer require topthink/think-captcha=2.0.*
./composer.json has been updated
Loading composer repositories with package information
Updating dependencies (including require-dev)
Package operations: 1 install, 0 updates, 0 removals
- Installing topthink/think-captcha (v2.0.2): Downloading (100%)

Invalid zip file, retrying...
- Installing topthink/think-captcha (v2.0.2): Downloading (100%)

Invalid zip file, retrying...
- Installing topthink/think-captcha (v2.0.2): Downloading (95%)
Downloading (connecting...)