What characteristics would you expect renewable/sustainable energy sources to have?

Assume that Mars and Earth are in the same plane and that their orbits around the Sun are circles (Mars is 23010^6km from the Sun and Earth is 15010^6km from the Sun).a) How long would it take a message sent as radio waves from Earth to reach Mars when Mars is nearest Earth?b) How long would it take a message sent as radio waves from Earth to reach Mars when Mars is farthest from Earth? Why we use semiconductor instead of metal in thermopile. The sum of two numbers is 49 and the difference between these two numbers is 9. What are these two numbers?Shown working out please How do Babette's and Maman-Nainaine's feelings about the figs contribute to the overallmeaning of the story? What should the equations look like for each number? 17-20 Name the given element.of lesson matter . There are 10 black balls and 15 red balls in the urn. If you take out a ball, what is the probability that it is black? five reasons why a girl child should be educated what occurs when the vapor pressure of a lquid is equal to the external atmospheric pressure Which TWO events happened at the same time? plsssssssssssssssssssssss help brainlist if you get my question right please I beg youuuuu. you will get 14 ppints four examples of primary sources of Mention population They are of a loaf of brown bread costs R6, how much will 4 halves cost? with balanced chemical equations, show the different stages of fermentation pls help me with this friends please solve this ASAP. I need this done but I can't figure it out what are perlemoen used for? Determine if thisgraph is anexample of afunction?? what is 2x 3 -7x^{3}7x 3 HELPPPPP MEE ASAP PLSSS Can some help with the answer please its very much needed and apprIeciated