Which best defines alternating waves of smooth muscle contractions that move food through the alimentary canal?

propulsion by peristalsis
propulsion by defecation
chemical digestion by peristalsis
chemical digestion by defecation

The media influences tobacco use by teens how? a) by showing beautiful, strong, and popular people using tobacco and cigarettes b) tobacco companies describing all the health effects of tobacco use c) cigarette businesses explaining all of the addictive qualities of tobacco use d) none of the above

Why is sustainable agriculture so important?

In a two to three page paper, examine the history and development of the healthy people initiatives. discuss some of the successes and shortfalls of the three initiatives thus far; including healthy people 2000, healthy people 2010, and healthy people 2020. be sure to include statistical data from the initiatives to support your position. don't forget to cite your sources.