The xylem of ferns and conifers contains only tracheids.

　　蕨類植物和針葉樹的木質部僅含有管胞。

　　Large proportion of xylem benefit to the water transfer.

　　葉脈中木質部比重越大，越有利于水分的傳輸。

　　A Review of the Study on the Developmental Biology of Xylem

　　植物木質部發育生物學研究

　　The length of the bars of the xylophone determines the different notes of the scale.

　　木琴琴鍵的長度決定音階的不同音調。

　　Basically they use different types of Africans Traditional music instruments such as xylophone made out of wood and Djimbe drum.

　　樂團表演所用的樂器基本立足于非洲各式各樣的傳統打擊樂器，如用硬木雕挖的木琴，世界聞名的金杯鼓等。