2/ Imagine building your own house. You don't need to manufacture your own materials. You just order everything you need: bricks, plumbing, tiles etc. To build a house you don't need to hire a brick manufacturing specialist - you just need someone who is able to use these bricks.
2/想象一下建造自己的房子。你不需要自己制造材料。你只需要订购你需要的一切：砖、水管、瓷砖等。要建造一座房子，你不需要雇佣制砖专家——你只需要有能力使用这些砖的人。