You can ask them to call back: can you call back in an hour?

你可以请他呆会再打过来：Can you call back in an hour ？

youdao

If you are rushed and cant talk, its better to say this and make plans to call back later.

如果你手头正忙无法说话,最好实话实说，告诉对方一会儿再打过去。

youdao

This is a timer method in which you specify both the interval of the callback and the function to call back.

这是一个定时器方法，同时指定了回调时间间隔和回调函数。

youdao

One wanted to call to these few soldiers to come back."

VOA: special.2010.07.15

There's got to be something back there, so we're going to call it "the unconscious" and we're going to try to describe it.

我们以后还会讲到这点,潜意识的作用。

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I'm going to keep coming back to that idea, but I'm going to call it computational thinking.

我会尽量回到这个想法上来，不过我将继续把它叫做计算思维。

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He said to call back on Monday when the agency should have more information.

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If you call before then, the IRS will likely politely (ahem) ask you to call back later.

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He called the emergency management agencies including the state units and FEMA. They were too busy to call back.

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