The amount of Nitrogen built up in the joint, as well as the strength of muscles around the joint, and the cartilage that holds that joint in place
Bottom of the stratosphere
The correct answer is - A. Desertification is increasing, and the desert is expanding.
The Sahara desert has been expanding in the past decades, and it has started to overtake territory south of it. This is mainly due to climate changes, the precipitation has been decreasing, the temperatures have been rising, so the desert has slowly crippled into the territories that were once steppes and savannas. There is an organized action from the people that leave on the borderline of the desert, where they have been thought some techniques as to how to stop the desert growing, and they have gladly accepted it and work hard on it. Initially it seems that there are positive results, but for sure only the time will tell.
