一直没打算入美国籍，不过想想以后要周游世界的话，看来还是要考虑考虑了。

by the way, blackbox, it is free to print as much as you want in the local library , but I still think they should set the printer with more option for the users, so as some people may like to save paper. I always want to save environment, and seldom use supermarket plastic bags. I use my own cloth bag.