如图所示是一观察太阳光谱简易装置,一加满清水的碗放在有阳光的地方,将平面镜M斜放入水中,调整其倾斜角度,使太阳光经水面折射再经水中平面镜反射,最后由水面折射回空气射到室内白墙上,即可观察到太阳光谱的七色光带。逐渐增大平面镜的倾斜角度,各色光将陆续消失,则此七色光带从上到下的排列顺序以及最先消失的光分别是
当你上学迟到时,你可以这样对老师说: A. It doesn’t matter. B. I’m sorry, I’m late. C. That’s all right.
当别人对你说“Your English is very nice!”,你可以说: A. Of course. B. Not at all. C. Thank you.
--When is the Teachers’ day in China? -- It’s on. A. September 10 B. December 25 C. October 31
—What’s the capital(首都)of the UK? A. London B. New York C. Paris
This is not my purse.is over there. A. My B. Mine C. I