Under F. A. A. guidelines, recreational fliers like Mr. Anderson and his customers must keep unmanned aircraft lower than 400 feet, away from other aircraft and within the operator's sight.

在联邦航空局的准则里有，像安德森先生和他的客户们娱乐飞行，必须使无人机在400英尺以下高度飞行，远离其它飞机而且在操纵者的视线之内飞行。

youdao

These verbs mean to keep from the sight or knowledge of others.

这些动词的意思是使别人看不到或不知道。

youdao

Hank: Yes, we must keep him on leash from now on. Farmers around here are likely to shoot on sight any dogs they catch worrying their sheep.

汉克：不错，由现在起，我们得牵着它。这里一带的农民，一见到豿儿骚扰绵羊，很可能会开枪射杀。

youdao

In the United States, people can fly model aircraft without approval from the Federal Aviation Administration if they keep the drone in line of sight, lower than 400 feet above ground and away from airports and air traffic.

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"For two, three days we will do our best to avoid Reyhanli residents and keep out of sight, " said Bilal Abu Daher, a refugee from the outskirts of Damascus.

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Inter Milan midfielder Sneijder had the first clear chance but, on this occasion, could not keep his long-range shot, from a free-kick, down - a common sight in South Africa as players struggle to tame the much-criticised Jabulani ball.

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