Ef course is ok, mainly depending on your diligence, because ef is available at any time within the specified time. In addition, if a friend recommends it, you and he can each send a month's course. As long as it is improved frequently, it will be quick. Personally, I learned it from scratch in Beijing ef, and chatting with foreigners after 1 year is basically no problem. In addition, I think the only person worth considering is Wall Street, and other English training is almost inferior. Go to New Oriental if you want to take the exam.