The flu is a virus that attacks your immune system when you are sick. While the flu virus is attacking however you start to get the regular symptoms of getting sick such as a feaver, coughing, vomiting and other things. But the reason why those things happen is because that is the reaction your body is giving off while your immune system is fighting off the virus. Which is why those symptoms stop when you get better.
1- the grass dies due to lack of food, from lack of photosynthesis from lack of sunlight
2- you danger the enviroment
In the small intestine, these cells contain microvilli, which are tiny hair-like projections that increase nutrient absorption. These projections increase the surface area of the small intestine allowing more area for nutrients to be absorbed.