If he scratches his head, you scratch your head.

如果他挠头，你也挠头。

She set her bucket on the ground, thrust her hand into her hair, and began slowly to scratch her head,--a gesture peculiar to children when terrified and undecided what to do.

她把水桶放在地上，把只手伸进头发，慢慢地搔着头，那是孩子在惊慌到失去主张时特有的姿态。 那已不是孟费?

It means to scratch your head in order to help you remember something you've forgotten.

这意味着你抓耳挠腮以使自己想起你遗忘的东西。

Cooking from scratch enables us to do two things that the Colonel can't: use great chicken and drain the grease more efficiently. This gave us a real head start, and the results were stunning.

烹饪从头学起，使我们可以做两件上校不能做的，使用好的鸡，还有放更多的油。

Hardly had she gone a hundred paces when she paused and began to scratch her head again.

她刚走上百来步，又停下来，搔着自己的头。