At long intervals, he drew his thumb along the edge of his knife, and nodded his head with satisfaction.

每隔很长一段时间，他就用大拇指摸摸刀刃，满意地点点头。

youdao

Practice with how much pressure needs to be put on the razor or if the thumb should hold hair against the razor's edge are each part of experimenting with this type of thinning out of hair.

这种方法需要反复练习，来摸准把头发按向刀刃的大拇指需要用多大力。

youdao

We did have to be somewhat mindful when reading an e-book, for example, as any accidental encroachment of the thumb onto the edge of the screen can trigger a page flip.

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An impromptu group gallop along the edge of a field led to a fall, and when I stood up my thumb didn't.

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