We perfected a hand-signal system so that he could keep me informed of hazards.

我们完善了一套手语体系，以便他能告知我危险。

《柯林斯英汉双解大词典》

The conducting motion is the main category of conducting method research and the conducting motion is mainly concentrated in the hand signal.

指挥动作是指挥法研究的主要范畴，而指挥动作的表现又主要是集中在手势动作上。

youdao

After the publication of the book, a drama scholar wrote to Mr. Unsworth asking for his source on the hand-signal system.

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When someone reaches toward you or uses a lot of open-hand gestures, it is usually a positive signal of interest and receptivity.

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Long before my translator - who is switching form Greek to Arabic to French - gets it right, Mr Lamhoud's hand movements signal what happened.

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