为WordPress评论/注册/登录等添加算术验证码 Math Captcha

Math Captcha 是一个非常不错的数学验证码插件，不仅可以给 WordPress 的登录、注册、找回密码、评论添加算术验证，还支持 bbPress 和 Contact Form 7 。可以设置算术的加减乘除法则，以及对已登录用户不启用等。

Math Captcha is a very effective and easy to use CAPTCHA for WordPress that seamlessly integrates into login, registration, lost password, comments, bbPress and Contact Form 7.

For more information, check out the plugin page or see the Support Forum.

Features include:

Select where to use math captcha: login, registration and lost password forms, comments, Contact Form 7 and bbPress
Hiding captcha for logged in users
Select which mathematical operation to use
Displaying captcha as numbers and/or words
Option to set captcha field title
Option to set captcha input time
.pot file for translations included