The students bombarded the teacher with so many questions that he couldn't answer them all.

bombarded 是动词 bombard 的过去式。bombard 原指"炮轰、轰炸"，这里用作比喻，表示"连续不断地提问"。这个词形象地描绘了学生们接二连三提问的场景，就像炮弹连续轰炸一样。