Please help me / the error arises every exercise


Uncaught ReferenceError: $ is not defined

Replace this line with your code. 


++ jQuery not loaded n china.... $ is not defined..

In China because of the GFW,many websites won't work correctly. So jquery failed to react in codes below
《script src="//"script》 --->these codes just can't work.

You can use "" instead or use VPN to 科学上网