Using the examples of the star thistle and the Kit fox, describe two ways roads can affect the environment.
There're mainly two harmful effects road construction has on our environment. The first one is that roads help some plants to move from one area to another. And the migrant plants then become a trouble for the existing plants in the area because the new-comers will compete with the local species for resources. A good example is the yellow star thistle in California. When there were cars driving down the road, the seeds of yellow star thistle got stuck in the tires and were then carried to new areas. They then competed with local species, which made it harder for local species to survive. Another is that the busy highways have become barriers for animals, and they divide up animals' habitat into smaller ones, where there usually isn't enough food to support the animal population. For example, the kit fox that feeds on mice and squirrels now get shut in smaller areas by highways and cannot get their food that is spread out over open grassland. As a result, its population has decreased. (173 words)
vt. 欣赏；感激；领会；鉴别 （appreciate的第三人称单数）
They don't have any confidence that houses will appreciate in value.(TPO49-20)