Back roofs are made from poplarandwillow wood. Straw or water-resistant local grass is used for thatch to help minimise heat loss.
顶部用杨木和柳木搭出架子，苫上稻草或防水的当地野草来最大限度地减少热量损失。
2
Poplarandwillow 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.
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％。
3
Formal agreements for cooperation were signed and new relationships were cemented for future collaboration with key poplarandwillow researchers, growers and users in Italy.