Astronomers build optical telescopes on tops of mountains because a. there is less air to dim the light. b. the seeing is better. c. CCDs work better with a beautiful mountain view. Astronomers build optical telescopes on tops of mountains because a. there is less air to dim the light. b. the seeing is better. c. CCDs work better with a beautiful mountain view. all choices, a, b and c choice c only choice a only choice b only choices a and b

choices a and b

Explanation:

Telescope can be defined as am optical instrument which is designed to observe the distant objects clear and nearer. It comprises of arrangement of lenses which allow the rays of light to be collected. The collected light is focused and the image so produced is magnified in the form of an image. The telescopes are prepared and manufactured on mountains top as this will help in preventing the distortion of light obtain from the star due to the fluctuation of air mass in the atmosphere. The atmospheric distortion affects the resolution, and affects the vision. The atmospheric pressure is low at the mountain tops so it will help in better observation of the sky.

an electric circuit

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.