The accumulation of several mutations in the main gene on the virus's surface may be able to give H7N9 the ability to spread like human flu viruses do, passing from person to person through coughing and sneezing.
When an object<span> is speeding up, the </span>acceleration<span> is in the same direction as the velocity. Thus, this </span>object has<span> a positive </span>acceleration<span>. In Example , the </span>object<span> is moving in the </span>negative<span> direction ( </span>has<span> a </span>negative<span> velocity) and is slowing down.</span>
There are four major reservoirs, or stocks, of carbon on Earth: 1) in rocks (this includes fossil fuels), 2) dissolved in ocean water, 3) as plants, sticks, animals, and soil (which can be lumped together and called the land biosphere), and 4) as a climate-warming gas in the atmosphere.