对不起，我没有时间。

我的学校开始，所以我很忙。我要练习中文，但是我觉得我没有时间。因为我有很多功课，还有我学习(Study?)考试很难。如果我不忙，就我要说话。

You know ,学校 in Chinese usually means school ,the place you study.If you want to express the point that you are taking a new semester,you can describe it as "我的新学期开始了".As for the third sentence,I guess your point is you have lots of courses to take,and they are so difficult to learn.If so ,you can say it as"因为我有许多功课，我觉得它们很难".There's a  morpheme sequence in the last sentence.We Chinese say 我就要 intead of 就我要.

If I need to raise my family ,maybe I will persist in this kind of job until I find a job that I'm interested in and can support my family at the same time

good for you

out of the passion of going abroad to further my study

First of all,I hope you can understand the meaning of our 4 tunes.Most ususlly,we use the character of one phrase to distinguish it from others.But sometimes we can also express our feeling by different tunes.An example at hand is the character 啊,by pronuncing it in different tunes ,you can express different mood.The second tune usually means you doubt about the words others tell you,or you are suprised.The first tune in most conversational occassions means you've got the idea of the speaker ,and you want him to go on.The fourth tune often means OK.In conclusion,it's not wise to practice 4 tunes alone.Only when you master the usage of it in conversation,can you really understand what a Chinese truely want to express.

Well,first of all ,I'd like to say,it must take a lot of carefulness for you to accumulate these phrases together.不如别人的人is a phrase which can work as a noun.It means a person who is not as well as others in some aspects.You know ,we all like to compare our lovers or firends or even kids with others',so if you want to express the idea that Jim is a person not as well as others,you can say"Jim 是个不如别人的人".But I strongly suggest you didn't use this phrase,because it deny a person completely,which means it will harm one's feelings a lot. As to the phrase低下的人,I have to admit that we don't use it separating from an noun.It usually comes after an noun which means one's personality or timber.If you want to say Jim is a person with poor moral character(in Chinese,we call moral character品德),you can say Jim 是个品德低下的人. When used as an adj,自卑 equals to self-abased,so when it's used as a noun,it surely means self-abasement. You can understand 差的 as bad,and 较差的means less bad.次的 is another way of saying 差的. 下级 is normally a subordinate,it's different from other phrases you ask .It doesn't show a negative feeling ,it just describes a relationship.

confused with your question ,could you try to express yourself more clearly?

On top of the priorities,I suggest Shanghai,for it's holding the Expo this year.What's more ,it's like the most developed city in China.The next stop I recommend Beijing,the capital of China.There are six dynasties in the history of China which chose Beijing as their capital ,so there are lots of interests here in Beijing.A more important factor adding to its attractivity is the Bird Nest and Water Cube which serve the Olympic held here in the year of 2008.As to the third choice,I sincerely recommend Harbin,the capital city of Heilongjiang Province,because its my hometown.It enjoys the honor of "the Ice City",for it's famous for Ice Laterns.People here are very friendly,you can enjoy the warmheartedness.Locating near Russia,there are a unique style of architech,which involved the best art style of both Russia and China.Beer Festival and Music Festival decorate the city with more cultural atmosphere.