ironworking

Research choices are often dependent on the specific civ, but you are going to want to get Iron Working and The Wheel sooner rather than later, just so you know where the iron and horses are.

研发的选择依赖于你选择的特定种族，但你需要尽快得到器(IronWorking)和轮子(Wheel)两项技，只有知道这两项技，你才能看到战略资源和马在什么地方。