1, normal, type what you see. If you can't read it, press ESC to skip

2, smart captchas, click the picture which match the given information.

3, recaptcha group, enter the numbers which match the given information, seperate each number with comma. Press F1 if there is no matching image.

4, confident captcha, type the low-case letters which match the tips, dont use commas or space to seperate it