2.11 graded assignment (tga): reasoning and proof - part 2

Earth's atmosphere is unique among the planets and is able to support life because it contains a large amount of a) oxygen b) helium c) methane d) carbon dioxide

17 a tourist was planning a trip by car for travelling at some constant speed for 2.5 hours. however, he found that if he increases the speed by 20 km/h he can cover the same distance in 30 minutes less time than it was planned. what was the planned speed of the tourist, in km/h?

Need will give 100 ! in no less than one hundred fifty words, explain why it is important for engineers to sketch designs and use them to clarify their designs to other people, giving at least three reasons.