London Bridge Is Falling Down - Henry and David has got a brand new toy, but they still don’t know how they have to assemble it!

Henry and David have received a big toy bridge, it's very similar to London's bridge. The problem is that they don't know how to build it up. Could you help them to make it better and faster? Surely you will know how to solve the problem, you're very intelligent kids! It's not a real bridge, it is just made of wood. However, they are a little bit nervous because they feel that they won't make it because it is too difficult for them. But there will be no problem because beside you and your help, everything will be better!