Actually, telling the truth in mathematics is of little use. I don't think it is necessary to do math or science research, especially functions, as long as you can do daily accounts and so on.

English: At present, many enterprises and institutions require CET-4 or CET-6 in their recruitment requirements, which may not be needed at work. However, with this recruitment threshold, many people have no chance to sign up and have many suitable jobs. But it also depends on what you want to do. If you don't start a job, it's not particularly important to open your own shop as a boss. After all, there are many foreigners in the city where we live now. If you want to go to work, you think you will have a chance to meet foreigners. Of course, English is better.