10. (3 points) There are three people, $A$, $B$, and $C$, who are a worker, a teacher, and an engineer, respectively. $A$ is older than the worker, $C$ is a different age from the teacher, and the teacher is younger than $B$. Therefore, the engineer is $\qquad$ .
【Answer】Solution: From the information that $C$ and the teacher are of different ages, and the teacher is younger than $B$, we can deduce that neither $B$ nor $C$ is the teacher, leaving only $A$ as the teacher;

From the information that $A$ is older than the worker, and the teacher is younger than $B$, it indicates that $B$ is not the worker but the engineer, so $C$ must be the worker; Therefore, the answer is: $B$.