If there are dots under the word, you can click on it to see it. Well, you need to do that the first time and the lesson tells you. And ling = zero as far as i know.
I don't get why we learn "ming, ne, me, etc" sithout getting that asked. So we don't know what that means and they don't ask for the meaning for that or teach it :/
You should inform students they will need to download/install the chinese character set to learn properly here. I had no way to type the chinese symbol "ba".... kinda silly!:P