### 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 large, the hard ball cannot stand up, and the master is difficult to control.
### Errors: There is a major error of incorrect translation is missing content from the correct translation at "Their strength is very low". There is a major error of incorrect translation includes information not present in the correct translation at "the ball hits the racket". There is a major error of incorrect translation has stylistic problems at "the vibration is very large". There is a major error of incorrect translation does not accurately represent the correct translation at "the hard ball cannot stand up". There is a major error of wrong grammatical register (eg, inappropriately informal pronouns). internal inconsistency (not related to terminology) at "the master is difficult to 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.