5physics questions for 25 points don't answer if you don't know it. i'll mark the best response as 1. a is an object in space with such intense gravity that no light can escape? a- red shift b- galaxy c- black hole d- nebula 2. a galaxy is a group of billions of stars, star systems, star clusters, dust and gas bound together by a- light b- gravity c- friction d- water 3. which of the following is not a type (shape) of galaxy? a- spiral b- triangular c- elliptical d- irregular 4. what is the shape of our milky way galaxy? a- spiral b- triangular c- elliptical d- irregular 5. there are billions of galaxies in the universe. how are they classified? a- by their colors and luminosity b- by their size and shape c- by their size and color d- by their size and brightness