secondary bast的用法和樣例：
例句
- The secondary phloem consisted of sieve cells and phloem parenchymas.
根的次生韌皮部則由篩胞和韌皮薄壁細胞組成。 - In the secondary phloem of Tree Peony metaphloem was dominative in the root's secondary structure, which was just opposite to Herbaceous Peony.
根次生結構，牡丹根次生韌皮部占主要部分，而芍藥根次生木質部占主要部分。
