A:氮气不支持燃烧
B:氮气不易溶于水
C:氮气的熔点是﹣209.9℃
D:空气中氮气和氧气的体积比约为4:1
—What do you think of your new job, Jim?
—It's _______. I do exactly the same thing every day.
如图所示,请在图中面出两条入射光线通过凸透镜后的折射光线.