他穿着沉重的登山靴在走廊上咚咚地走着。

He was ___stomping down the hallway in his heavy hiking boots.

这道数学题太难了，把全班同学都难住了。

The math problem was so difficult it had the whole class ___stumped.

市长候选人正在全县各处发表演说拉票。

The mayoral candidate is ___stumping across the county to win support.