这个礼拜的Quiz:
During the sunset, you might see the green flash atop the yellow and red images of sun for a couple of seconds.
1. Those images shown here are not round but flattened.
2. The blue flash is very rare.
3. The green flash is atop the other yellow and red images. Make a sketch to explain.
4. Spot size of green spot < yellow spot < red spot?
(内容好多。。。先留个记号,之后再都转过来)