Tom is a student ( ) No.2 Middle Student.
不可以用in,如果非要用in,就是：Tom is a student who is in No.2 Middle School.
我在读中学.I'm studying in a middle school.第二题可否用一般现在时？可是可以吧，但总觉得I study in a middle school有点别扭。。。个人认为I'm studying in a middle school. 挺起舒服些~呵呵