Answer:
Guarantee that you will be hired for a job.
Explanation:
A mentor is an older, more experienced person who spends time with you in order to transmit the knowledge he has about a particular area you are interested in. This is usually career-related. Mentors can give you valuable advice to apply in your daily life. They can also introduce you to potential employers. However, what a mentor cannot do is that he cannot guarantee that you will be hired for a job.
