I want to major in biology because I have long wondered about the origin of life.

我想要主修生物学，因为我一直在思考生命的起源。

You should major in computer science in the future if you are so interested in it.

如果你对计算机科学那么感兴趣的话，你应该主修这个专业。

In fact, I want to major in English in college and to be a bridge between China and the world.

事实上，我想在大学主修英语，这样我就能成为连接中国和世界的桥梁。

I made up my mind to major in English in the future after consultation with my parents and teachers.

在咨询了我的父母和老师后，我决定以后要主修英语专业。

My brother laid a solid groundwork for French at high school, so he decided to major in French at university.

我哥哥在中学就打下了很好的法语基础，所以他决定在大学主修法语。