Answer:
bridge,for,and eye or enclosure
Carbon dioxide is added to the atmosphere naturally when organisms respire or decompose (decay), carbonate rocks are weathered, forest fires occur, and volcanoes erupt. Carbon dioxide is also added to the atmosphere through human activities, such as the burning of fossil fuels and forests and the production of cement.
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.
Lecithin is (organic chemistry) the principal phospholipid in animals; it is particularly abundant in egg yolks, and is extracted commercially from soy. It is also a major constituent of cell membranes, and is commonly used as a food additive (as an emulsifier). While cephalin is (biochemistry) a phospholipid found particularly in the cells of nervous tissue; it is also the primary phospholipid in bacteria.