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In elementary school, students typically have one teacher for all subjects. In middle school, they begin to change teachers for each subject. One person teaches them math, another teacher social studies, and so on. Students walk to a different classroom for each subject. That means they get more exercise!
It is likely that:
a) All middle school teachers must be able to teach science.
b) In middle school, the English teacher and math teacher may be different people.
c) Elementary school teachers are smarter than middle school teachers.
What is b) In middle school, the English teacher and math teacher may be different people.