The sky was dark blue and clear when the moon came up.

月亮出来时，天空是深蓝色的，非常晴朗。

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Blue sky, clear lakes, green grasslands and snowy mountains are all our treasures.

湛蓝的天空，清澈的湖水，碧绿的草原，雪山，都是我们的财富。

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The air was crisp and clear and the sky was blue.

空气清新，天空碧蓝。

《牛津词典》

The next day the sky was blue and clear.

VOA: special.2009.02.28

The sky was just a little lighter blue than his suit, clear and even with only one cloud in it, a large, blinding white one with curls and a beard." Notice that image of the cloud, the blinding white cloud.

天空比他身上蓝色的西装颜色更亮，更清朗，甚至,空中只有一朵白云，是大而亮白的螺旋状和,胡须状，注意这多云的图像，一朵亮白的云。

耶鲁公开课 - 1945年后的美国小说课程节选

And for all Thursday's celebrations - big and small the skies in Beijing were clear and blue, a striking departure from the heavy fog of a day earlier.

VOA: standard.2009.10.01

Targeted at private users and professionals alike, the deep-blue LUMILEO devices project large, clear and crisp pictures from a wide choice of sources.

ENGADGET: Toshiba outs Lumileo pico projectors, only one of which requires a plug

It was all thanks to a large dome of persistent high pressure, clear blue skies and strong sunshine.

BBC: Spring equinox today but winter lingers

The architects painted the cables white, so that they would disappear into the sky on overcast days, and complement the blue of clear skies.

WSJ: A Concrete Ribbon Through the Clouds | Millau Viaduct | Masterpiece by Joseph Giovannini