答案：C

题目分析：考查过去分词做定语：变为陈述语序 those seated at the back of the classroom can hear me. seated at the back of the classroom修饰those，those指代人，人与seat的关系是被动，某人坐下是seat oneself，所以用过去分词修饰，意思是：坐在后边的同学听到我说的话吗？选C。

点评：做定语时要注意不定式的被动，表示将要被，现在分词的被动表示正在被…，过去分词表示已经被…,做题时要结合上下文来选择。