1 交了I140後是不是有移民傾向，不能申請B簽證來美了？
-Just try to see whether you are lucky or not.
2 我在國內的時間是不是都算服務期？累計超過兩年就可以？
-Depends on how long every your visiting US. For example: if you stay in Chinsa for 6 months, and you visit US and stay here for 3 or more months, then the 6 months you stayed in China may not be counted服務期 (your 服務期 becomes zero). But if you only come to US and stay 20 days (short time), then the 6 months you stayed in US will be counted as 服務期. So, it is somewhat complicate and if USCIS say Ok, that is OK. But if they say, not OK, then it is not OK.
