Certainly, every person has bad habits. Some people may be in the habit of speaking rudely; some tend to be deaf to others’ opinions; some are inclined to delay. However, there is no doubt that allowing to be controlled by bad habits does a great harm to personal development.
It is not too much to say that it is a destructive behavior to allow to be controlled by bad habits while it is constructive to change unwanted habits. If bad habits are allowed to be developed, they will get out of control and become big obstacles to life or career. For example, a delayed-prone person will hardly restrain himself from missing the deadline. Understandably, he will have few chances to be entrusted with important tasks and then will barely be professionally experienced enough to gain promotion. On the contrary, it is beneficial to change unwanted habits and acquire good ones, because good habits can make people more competent and thus widen the door to success.
In summary, bad habits will probably make it impossible for us to achieve our ambitions. Therefore, we should be alert to our bad habits and make persistent efforts to break them.
写作思路：
开篇指出虽然每个人都有坏习惯，但是放任坏习惯对于个人发展十分不利。第二段继续论证放任坏习惯对生活及事业的危害以及改正坏习惯的必要性，且举例说明。结尾进行总结，强调主题。
亮点表达：
1.be in the habit of doing sth. 有做某事的习惯，或习惯做某事
2.be deaf to sth. 对某事充耳不闻
3.be inclined to do sth. 同义于tend to do sth. 有做某事的倾向,也就是习惯做某事
4.there is no doubt that+句子 毫无疑问的是
5.It is not too much to say that+句子 毫不夸张的是
6.destructive 破坏性的;constructive 建设性的
7.restrain sb. from doing sth. 约束某人做某事
8.be alert to sth. 警惕某事
