A:虚像是人的幻觉,实际上并不存在
B:人能看到物体是因为人眼发出的光射到物体上
C:实像可在光屏上显示,虚像不能在光屏上显示
D:实像和虚像都可在光屏上显示
⑴____ A. book B. good C. food D. classroom
⑵____ A. pens B. teachers C. apples D. cats
⑶____ A. like B. history C. Friday D. time
⑷____ A. decision B. station C. attention D. pollution
⑸____ A. happy B. family C. what D can
How does the boy like the concert?
空气质量的好坏,一方面受自然因素的影响,另一方面还受 ( )