annual weed的用法和样例：
例句
- It is non-selective, which means it kills a wide range of annual grasses and broad-leaved weeds and the tops of established perennial weeds.
具有非选择性，意味着可以根除多数的一年生杂草和宽叶种子并保持长效作用。 - Any of several annual weeds of the genus Xanthium in the composite family,having small seedlike fruits enclosed within a prickly bur that clings readily to clothing or animal fur.
苍耳，一种菊科苍耳属的一年生杂草，有包在多刺的刺果内的种子样小果实，其刺果易于粘到衣服或动物皮毛上。
