B)下列5题中的句子可以组成一篇小短文,请从所给的四个选项中选出可以填入空白处的最佳答案。(答案涂在答题纸上) Faraday made the ________ electric motor in 1821. It was an invention that used electricity to produce movement. A. obvious B. social C. mad D. first
Some people say that Mars should be protected as a wildlife reserve where we do everything possible to avoid pollution, on the _______ that life could exist on it.