Sandstorms aren't the only source of sand in the air.

沙尘暴并不是空气中沙子的唯一来源。

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Lichen fields-blooms of orange and gray over red sand and crusts of blackish gypsum-keep the soil stable and are a critical source of food for invertebrates.

地衣区是指红色沙石和黑色石膏地表之上的橙色及灰色植被区，它能稳固土壤，是无脊椎动物最关键的食物来源。

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Sand, significant in the final colour of the concrete, came from a single source and was stored at the local producers to ensure maximum uniformity of colour.

沙子对混凝土的颜色有重要影响，采场单一、由本地的生产商负责以保证颜色最大的均匀性。

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He said its closure would hit "the only source of employment in the area, mainly local sand and gravel companies which traded with the Republic".

BBC: British favoured closing Aghalane Bridge