经过近一年的努力，今天我和太太终于在广州通过了面试，我准备在6.20来美国，请问八老师以下几个问题：
1、我持移民签证来美后，在还没有取得绿卡的时候能否去加拿大旅游？
1、我持移民签证来美后，在还没有取得绿卡的时候能否去加拿大旅游？
-Yes. Just show the endorsed immigrant visa stamp on the passport to travel and reenter US.
我有加拿大的十年旅游签证的。-Not need the visa to visit Canada in this case.
2、由于我现在国内仍然还有工作要做，6.20来美后，9月上旬需要回国，明年2月初再来美，然后住两个月后再回国住两个月，这样每年回国两次（春季和秋季），是否需要申请回美证呢？
-I think so.
3、听说回美证只有两年有效期，且只能办两次，是这样的吗？-No law limits that, but if you apply for more than twice continuously, USCIS may not approve it unless you have very strong reaqson, e.g. you work for a US employer and the employer send you to work in China.
谢谢！
3、听说回美证只有两年有效期，且只能办两次，是这样的吗？-No law limits that, but if you apply for more than twice continuously, USCIS may not approve it unless you have very strong reaqson, e.g. you work for a US employer and the employer send you to work in China.
谢谢！
