< p >什么是云的形成< a href = " https://video fra3 - 1. - xx.fbcdn.net/hvideo xpf1/v/t42.1790 2/11015023_903265136402907_1288638676_n.mp4?efg=eyJybHIiOjMwMCwicmxhIjo1MTJ9&rl=300&vabr=144&oh=4ae988ce8a46829aa85215887105a8ff&oe=55AD0D67" rel="noreferrer">in this video? I don't know where this footage was taken. Here's the link to the video again.