My Chinese teacher gave us a small assignment to find what letter from our alphabet isn't used in Chinese.

I can't seem to find a good answer...could someone help me?
I already know that Chinese doesn't use the alphabet I use in America..what SOUND, that we associate with an a letter in the latin alphabet, is not used in Chinese?

I will be a senior this year in high school. I would like to find a good college in Missouri that offer a Chinese language program. I want to continue learning Chinese after high school because I want to become a Chinese language interpreter and later on a Chinese teacher. I want to find a nice College that will offer an exchange program so I can go over to China/ Taiwan to study. So can anyone recommend any colleges?