This phenomenon typically occurs over open terrain on a day with clear skies and calm winds.

这个现象在晴朗和微风的日子及在空旷的环境比较容易出现。

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Cultural Square in front of for the city, Xinhua Bookstore north, the south road of peace-commerce street location convenient transportation and beautiful environment, open terrain.

门前为市文化广场，北望新华书店，南临和平路商贸一条街，位置优越、交通便利、环境优美、地势开阔。

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Terrain : southeast to the northwest, high low open.

地势：东南高西北低，向大西洋敞开。

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Explore trails of both wooded and open terrain as you take in the fragrant landscape.

BBC: Daily deal: Verdant gardens steeped in lowcountry history

Unless you are in open terrain, it's hard not to find one of these boxes around.

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Field tests of the CT2WS system were conducted in desert terrain at Yuma Proving Ground in Arizona, in tropical terrain in Hawaii, and in open terrain at California's Camp Roberts.

ENGADGET: DARPA threat detection technology uses a camera to see targets, software and soldier brains to identify them