Question

7. —Can those        (seat) at the back of the classroom hear me?

—No problem.

Answer 1

7. seated此處seat為及物動詞，常與反身代詞連用或用be seated的形式。這里seat與those構成邏輯上的被動關系，故用其過去分詞作定語，those seated at the...是those who are seated —的省略。