1.There isn't a subway system,__there is a very nice railway

1.There isn't a subway system,__there is a very nice railway station.A.but B.and C.or D.because
2.Don't forget __the window.
A.to open B.opening C.opens D.opened
3.The boy is __young to carry the box.Let's go and help him.
A.too B.very C.quite D.so