蚯蚓适应土壤穴居生活的特征有哪些?
参考答案:
头部退化,具口前叶,体表有角质膜和粘液、刚毛。
18英寸等于()mm
The project plan is developed by ______.
A) the project managerB) the manager of project managersC) the project teamD) A and C