Dark matter is observed by the gravitational effect that  it has on radiation and the visible universe. The gravitational  force it has from dark matter plays a critical role in the shape of  the galaxies orbit and the because of the hot gases in the groups  of galaxies.
The Angus breed is perhaps the most used, most well-known breed of beef cattle in the U.S. With origins in northeast Scotland, Angus, also known as Black Angus, is popular among Brits and Americans and was first imported to the United States in 1873.
Q: How is beef graded? A: Independent USDA graders inspect cattle and label them according to the grading scale: Prime, Choice, Select and several low-quality grades. A: The same independent USDA graders inspect black-hided cattle (typical of the Angus breed) and give it a grade. All beef considered for the brand must be the best Choice, or Prime, beef â truly the top of the scale.