我来试着回答一下这个问题吧！
个人觉得How long is it?的答语应该是It's about 8，000meters long .
在初中英语中，我们都知道长宽高深重的表达法，可以直接用数词＋米／公里＋单位词。
如：The classroom is about six meters long，five meters wide.
The Tian'anmen Square is about 4，400 meters long from south to north.
我们可以这样来提问：：：How long is the Tian'amen Square?
希望我的回答能够尽快帮助到你呀！
