What do radio telescopes use to gather and focus radio waves?

(328 inc. 448 ind. 480 in25. john has a collection of toy cars. he has 2 red cars, 4 blue cars, 4 black cars, and 6 yellowcars. what is the ratio of red cars to yellow cars? a. 1: 2b. 1: 3c. 1: 626. the net of a right triangular prism is shown below.