Why did the Soviet Union think a lightweight, automatic rifle was needed?

为什么苏联认为一件轻型的、半自动的武器是人们需要的？

Now he chats with his plain clothes rebel comrades next to a gun-mounted pick-up truck, hoisting a Belgian-made FN light automatic rifle that's half his height.

如今，他的手里拿着一把有他身高一半长的比利时制FN自动步枪，站在一辆皮卡战车旁与身着平民服装的反抗军同志们聊着天。

The US Army uses two distinct families of weapons in 5.56 x 45 mm calibre: the M16 rifle and the derivative M4 carbine form one group, the M249 Squad Automatic Weapon the other.

美国陆军使用两种截然不同的5.56毫米口径木仓族：一种是M16步木仓以及其派生出来的M4卡宾木仓，另一种是M249班用机木仓。