Firstly,each person is like a screw of the machine. 改为 Firstly,each person is like a screw of a machine. 上下文没有提到具体是什么机器，所以不用冠词the。 And several tasks call for the cooperation of all the members of the group. 改为 Tasks require cooperation of all the members in the group. 不知道你这里为什么要用several，我觉得直接Tasks开头会更好。of不到不得已不要嵌套使用。 Performing your own tasks carefully,keeping pace with your classmates or colleagues and listening to others' suggestions help you succeed in the end. 改为 Performing your own tasks carefully,keeping pace with your classmates or colleagues, and listening to others' suggestions help you be succeed in the end. 语法错误