One's deceased father grind mathematics Zhang Yu's data only did 1000 questions, and did not practice behind closed doors. Is this ok? I think many other people still practice behind closed doors.
To tell the truth, the problem is not to do more, but to understand thoroughly and really do it. Zhang Yu's question may be more difficult than Tang Jiafeng's and Li Lin's. 1000 If you don't do anything else, it's not a big problem to try it twice or three times. Brother Yu's style is mainly to understand the concept thoroughly and use it flexibly, while Tang Jiafeng's questions can exercise his computing ability a little more.