检查以下文章的语法错误 - 提高你的写作水平 - 常规

以下是文章中的一些语法错误：

'It is a common, which shows' 应改为 'It is common, which shows'
'Although someone agree with that' 应改为 'Although some agree with that'
'while I disagree with that' 应改为 'while I disagree with that.'
'but I think that this is a useless item for the students' 应改为 'but I think this is a useless activity for students.'
'Firstly, the volunteer is an unnecessary subject in the school' 应改为 'Firstly, volunteering is an unnecessary subject in school.'
'One of key reasons is that if it is taken into the study assign' 应改为 'One of the key reasons is that if it is included in the curriculum.'
'In other words, it will reduce the time, which should be cost on the academics' 应改为 'In other words, it will reduce the time that should be spent on academics.'
'The high grades have some advantages for the getting the decent cares' 应改为 'High grades have advantages when it comes to getting decent careers.'
'Compared with the students, this type of the service should be played by more professional stuffs' 应改为 'Compared to students, this type of service should be performed by more professional staff.'
'Because the employee has more skills about to care the person' 应改为 'Because employees have more skills in caring for people.'
'On the other hands' 应改为 'On the other hand'
'If it became an obligatory item rather than the obligation' 应改为 'If it becomes an obligatory item rather than an option'
'it will change the means of this activity' 应改为 'it will change the purpose of this activity.'
'Furthermore, the students maybe boredom of the charity' 应改为 'Furthermore, students may get bored with charity.'
'if there are so many works for them' 应改为 'if there is too much work for them.'
'Even thus it became a necessary item for the children' 应改为 'Even though it became a necessary item for children.'
'sometimes they may destroy some public installations to reduce their stress, which be bought by the so heavily works on the study and the charity' 应改为 'sometimes they may destroy public property as a result of the stress caused by heavy workloads in studying and doing charity.'
'Hence the community service should be decided by t' 需要补充完整。