Task 6【名词解释】：老师讲很多farmers讨厌在他们的crops 旁边长weeds，但是其实它有助于crops成长。【教授举例】：用咖啡举例子，帮助protect fertilized soil wont be flushed away by water. Prevent coffee’s leaves from being eaten by insectsweeds protect coffee的原因是 insects prefer weeds than coffee