1)Be sure to write to us,______?A.will you B.aren't you C.can you D.mustn't you

1)Be sure to write to us,______?A.will you B.aren't you C.can you D.mustn't you
2)Charles Babbage is generally considered______the first computer.
A.to have invented B.inventing C.to invent D.having invented
3)Tony is going camping with ______boys.
A.little two other B.two little other C.two other little D.little other two
懂的来说下,
请把原因写出来啊，为什么选XXX。