Deforestation leads to environmental imbalance. Give reason.

Well, deforestation is cutting down trees, and many arboreal animals live in those trees. So if they have no proper shelter, they would have no place for personal activities such as breeding, feeding etc. And without those important activities that they have to do everyday, the population of arboreal animals will keep on decreasing until they go extinct. Though that's not the only problem. The herbivores won't get anything to eat, hence not letting the omnivores or carnivores get their food. As you can see, deforestation can create a huge environmental imbalance.

what statement best describes the difference between the sympathetic and parasympathetic nervous systems?

the sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. the parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.