随着空气相对湿度的增加，导管分子长度和直径均增大，射线频率减小。
With the increase of relative humidity, both length and diameter of vessel element increased, as well as the frequency of rays.
纤维分子长度普遍大于导管分子长度，而纤维分子的口径也普遍小于导管分子的口径。
The longer the vessel molecule is, the smaller the aperture is, the shorter the vessel molecule is, the bigger the diameter is, the length of the fiber cell is longer.
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