拜占廷与东斯拉夫人的交往（6—9 世纪）可为两个时期。

Association between Byzantium and East Slavs(6th—9th) divided two periods.

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南斯拉夫共有杨柳树林地15万公顷，仅占森林面积的1.5％，但其木材产量却占全国木材总产量的8％。

Poplar and willow forests in Yugoslavia have an area of 150,000 ha, being 1.5% of the national total, but the timber output is 8% of the gross national production.

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