第一段有三个拼写错误：conclusion,first,scrutiny.
第二段个人认为分析不到位,可加上这样一段：Without the evidence showing that antibiotics have the effect to prevent patients from secondary infections,the arguer fails to support the causal relationship between the hypothesis and the study.
第三段拼写错误：first； 且倒数第二句话because of 部分个人认为语义含糊,可改为：because of the former's higher efficiency of hormone secretion and metabolism.
第四段拼写错误：shortened；另外,本段缺少一个总结句,如：Since all these cases not clarified,the conclusion that the antibiotics are the key to the shortened recuperation time of the first group.
第五段拼写错误：attributable,possibilities,beneficial；另外,该段论证的观点很好,但个人以为在写法上有些偏了,如首句可改为这样：Finally,even if the shortened recuperation time is attributable to the use of antibiotics for patients of the first group,the arguer emphasizes too much on the use of antibiotics by drawing the conclusion that all patients who are diagnosed with muscle strain should take antibiotics,since antibiotics may have side effect on patients and cause anaphylactic reactions.
另外,原题还有一个漏洞就是两组的主治医生不同,一个是运动医药医生,而另一个是全科医生.当然,不写这一点可能也差不多了.
最后,少了一个总结段,应该补上,如：To sum up,the argument is unconvincing as it stands.To support the causal relationship between the hypothesis and the study,the arguer have to give evidence that antibiotics have the effects to prevent patients from secondary infections.To better assess the argument,it's necessary for me to know that the two groups are innately and externally identical.Also the arguer should reckon with the side effects and anaphylatic reactions of antibiotics when advises the use of antibiotics on muscle strain,which will make the conclusion more persuasive.
这样一来,全文结构就很完整了,而且字数也能达到五百以上.
希望对你有所帮助.