I run npm start, the localhost:8080 doesn't work,
but I run http-server -c-1 -p 8080, the website is OK.
I think npm script concurrently has some thing wrong,
but I don't know how to fix it.
does it work with
npm run-script start ? 
does it work with
npm run-script start?
It doesn't work.

@linbingquan You are on Windows, right? I had the exact same issue with http-server and Windows in context of another project. There is currently an issue with this npm module, see
https://github.com/http-party/http-server/issues/525
Although many devs are affected, the bug has not been fixed so far. The workaround is to use explicit URLs like http://localhost:8080/examples/index.html. 
@mrdoob An other option is to downgrade the npm package in package.json to 0.9.0. However, this will cause some security issues (meaning npm and github will complain).
It seems they haven't updated the npm package yet.
The fix is now published as http-server version 0.12.0, new installs should be good to go
See 0998172670b1a385bacba16cbd7145aa1aa662bd
Most helpful comment
See 0998172670b1a385bacba16cbd7145aa1aa662bd