?上学

... I had known nothing about it until then.直到那时我才知道这件事。 to go to school上学 from beginning to end 自始至终 ...

?上学去

... in town在城里， to go to school上学去， to go to bed去睡觉， ...

?该上学了

是在一个自由国家中 ? Is in a free country 该上学了 ? To go to school 我们甚至可以打扮成魔鬼吓唬人 ? We can even dressed as a devil scaring people ..

?上学了

上学了 ? To go to school 忘记该忘记的 ? Forget the forgotten ..