birch GREGMAT专八

They’ve got a wonderful birch in the back garden.

他们在后花园有一棵极好的树。

In midmost of the stream, embraced in the weir's shimmering arm-spread, a small island lay anchored, fringed close with willow and silver birch and alder.

在大坝那闪光的臂膀环抱中，安卧着一个小岛，四周密密层层长着柳树、白和赤杨。

That means the birch from high longitude and latitude areas will have lower content of the ash, extraction and lignin, higher content of the holocellulose and pentosan in the wood.

这表明，选择较高经区的白，可以降低灰分、抽出物、木素含量，提高综纤维素和聚戊糖含量。