帮忙解决几道英语题 急！！

1.---Would you like to go and see the film with me tonight?
---Thanks,but I _B__ it already.
A.saw B.have seen C.see D.will see
2.---Jack,I haven't seen your brother for a long time.
---He __C__ Shanghai on business for two months.
A.went to B.has gone to C.has been in D.has been to
3.A/H1N1 flu is terrible, but our government __A___ action to pervent it already.
A.has taken B.took C.will take D.was taking
4.这本书我已经读了两小时，但我还没读完。
_I___ _have___ _read（完成时态）___ this book for two hours, but I _haven't___ __finished__ it.
5.我整个下午都在写信，到目前为止写了五封了。
I __have__ _been___ _writing___ letters all morning and _have___ _written___ five letters so far.