### Chinese: 它们强度很低，球打到拍子上面，振动非常大，硬球顶不住，高手都很难驾驭。
### English: Their strength is very low, the ball hits the racket, the vibration is very big, the hard ball can't hold it, and it is difficult for the master to control it.
### Errors: There is a major error at "hits the racket". There is a major error at "big". There is a major error at "the hard ball can". There is a major error at "t hold it". There is a major error at "master". There is a major error at "control".

### Improved English: They are low in strength, and there will be too much vibration when the ball hits on it; it cannot withstand hard balls, and even professional cannot handle it.