IELTS, IELTS!
Sorry again, I can't type Chinese on this computer because I am not at home.
I think it is not true that English speaking teachers are always the best teachers. You need teaching fro ...
good idea
for native teachers English is a born gift; for Chinese teachers they must have taken a great deal of efforts to acquire this skill. so they may give insights and methods more relevant to learners.
regarding freshness of English lanuage; reading magazines such as times, newsweeks, as well as watching new movies would help a lot. for example i just know asap is pronounced as a-sap, i thought it should be a-s-a-p before i heard a-sap in a movie lately