guarantee

/ˌgɛrənˈti/

a written assurance that some product or service will be provided or will meet certain specifications

中文释义：保证；担保；保修单

The product comes with a two-year guarantee against manufacturing defects.

该产品附带两年保修，针对制造缺陷。

Hard work is no guarantee of success, but it certainly helps.

努力工作并不能保证成功，但肯定有帮助。