请问为什么要把寄到Phoenix，AZ的485、131和765“routed to the Texas Service Center for processing”？
我的PD是08年4月，去年12月30号用FedEx寄出I-485到Phoenix，AZ。Tracking显示邮件于一月三日被签收，今天收到以下电邮。请问为什么要“routed to the Texas Service Center for processing”？难道Arizona Service Center 不能 processing 吗？那为什么要我们寄件到Arizona Service Center 呢（我在Idaho）？
谢谢回答。
Dear Applicant/Petitioner:
Your USCIS application/petition has been received and routed to the Texas Service Center for processing. Within 7-10 days by standard mail you will receive your official Receipt Notice (Form I-797) with your Receipt Number SRC129009xxxx. With the official Receipt Notice (Form I-797) you may visit www.uscis.gov where you can check the status of your application using My Case Status. We suggest you wait until you have received your Form I-797 before checking My Case Status.