求英语高手来帮我看看这些句子有没有错误，或者可以改进的地方

1、表示“在下文中”用in the article below比较好，原文会理解成“在文章的下面”（纸的下面）
2、语法完全混乱，No matter 后面要接句子， life 是名词后面怎么接how？ opportunity to efforts 中to后面应该接动词，总之就是不知道你要表达什么
3、此处 need 是不可数，不能用many，而应用much，不知道你用of place 是表达什么，to后面应该接动词或名词， 后面应改成I List some matters needing attention when studying and living in the United States.
4、our life改成we, 因为life自己不会“遇到”问题，如果要表示生活上遇到问题，可说in life in the United States.

1.introduces改为introduce，I是第一人称，动词不用第三人称形式。
2.No matter how many merits and demerits if we study and live in the United States , we should grasp the opportunity to improve our comprehension of different culture
3.It is of great importance to pay attention to the place for studying and living in the United States. I List some matters needing attention when studying and living in the United States.
4.改成这样可能更合适一点：If we pay attention to points above（above是副词）, our life will not meet some unnecessary troubles（some，要用复数形式） in the United States。其实这句话这么表达会更好：If we pay attention to points above, we will avoid some unnecessary troubles in the United States