A. boy.
B. It's black.
C. Yes, he is.
D. Her name is Li Hua.
E. She is my English teacher.
如图所示研究光的折射现象,激光笔射出的光从空气中斜射入半圆形玻璃砖,图中的折射角是 ____ 度,当入射角增大时,折射角将 ____(选填“增大”、“减小”或“不变”),在光屏上看到折射光线亮度 ____(选填“大于”、“等于”或“小于”)入射光线亮度.
对光完成的标志是要看到明亮的圆形视野.(判断对错)
下列关于现代类人猿与人类区别的叙述,不正确的是( )
—Are the beaches in Dalian beautiful?
—Sure. They___________ lots of tourists from home and abroad every year.