She insinuated her right hand under his arm.

她悄悄把右手插到他胳膊底下。

《牛津词典》

Molly was on the bed, one hand under her head.

莫利躺在床上，一只手枕在她的头下。

youdao

Helen’s breakthrough came when Annie held her hand under a water pump while spelling “water” into her other hand repeatedly.

有一次安妮把海伦的手放在水泵出水口下，并且在她的另一支手上重复拼写water 的时候，海伦突然明白了，她的学习有了重大突破。

youdao

I put Helen's hand under the cool water and formed the word w-a-t-e-r in her other hand.

VOA: special.2009.11.08

When the meat got all warm and sticky in her fingers, she rinsed her right hand under cold running water and started again.

NEWYORKER: Luda and Milena

Out came her hand from under the sheet.

NEWYORKER: Beginners

You know the pose: a woman holds her drink or a pen in one hand, her other arm is crossed over her waist, tucked under her elbow.

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