英语语法分析

The primitive exarch and diarch haplostele with cross-like metaxylem exists in the lower part of CNZ.

在子叶节区下部存在原始的外始式二原型十字形单中柱。

Haplostele a type of protostele having a solid strand of stele with the xylem on the inside encircled by phloem pericycle and endodermis.

单中柱：原生中柱的一种类型，是由韧皮部、中柱鞘和内皮层包围着内方的木质部构成的实心中柱。