His smartness of the morning had seemed to Tom a good joke before, and very ingenious.

汤姆之前觉得他早上耍的小聪明是个很好的笑话，而且很有独创性。

What is the secret of his smartness?

他们聪慧的秘密是什么呢？

He seemed impressed by her smartness.

他似乎被她的不俗仪表所打动。

You just ain't using that smartness .

你就是没有用到你的聪明。

This is a characteristic of the child, the smartness.

这就是孩子的特点：机灵。