You have to pull a rope to open a cannon. Why can't you fire it with one click? Why haven't the 21s 

All the videos produced by this channel are designed to convey interesting popular science knowledge to the audience and are absolutely in line with the platform's usage policy.
Hello everyone I am your ”Encyclopedia Uncle” Rocket Uncle ~
Talk about interesting science and teach creative people!
Through the description of natural science and social science knowledge outline the overall outline of the scientific knowledge picture!
If you want to know more knowledge please do it in [Uncle Scientific Rocket]]
Science and Technology Culture-Technology And Culture: • 科技文化-Technology And Cu...
Life Science Popularization-Life Science: • 生活科普-Life Science
Animal Science-Animal: • 动物科普-Animal
Dry Goods Explanation: • 干货讲解
Planet Culture-Planet Culture: • 星球文化--Planet Culture
Gadgets: • 小玩意
Rocket Uncle Teach Science: • 火箭叔教科学
Astronomy-Astronomy: • 天文学--Astronomy
---------------------------------------------------------------------------------
If you like me subscribe to me. Don't forget to click on the little bell🔔Your support is precious to me!💨
kexuehuojiansh...
Science Rocket Uncle# Science Popularization# Culture