natural age自然年龄naturaladj.自然的；天然的；私生的natural communication behavior自然交往行为natural gas liquefaction plant天然气液化厂natural self-supporting arch自然平衡拱natural gas purification plant天然气净化厂natural moisturizing component天然保湿因子natural gas with high nitrogen高氮天然气natural binary-coded decimal自然二进制编码的十进制natural population growth rate人口自然增长率natural enemy exclusion method天敌排除法natural secondary mixed forest天然次生混交林

1. Jagged rocks stuck up through the grass.
   锯齿状的岩石从杂草中突了出来。
2. He is in taller grass and weeds.
   他走在更高的草地和杂草中。