请教8老师，关于I-864等问题

看了老师昨天给“香侬”有关I-864的回答，有点糊涂。

关于下面这个，老师说不用选。可是如果这样，item 10就该填“1”，household size不就少了一个人（父亲或母亲）吗？

part 3 item 9 :

I am sponsoring the following family members immigrating at the same time or within six months of the principla immigrant named in Part 2 above. Do not include any relative listed on a seprate visa petition.

第二个问题是，我给父母申请绿卡，收到USCIS的I-797C（receipt notice)已经有一周多了，可是在“My Case Status"里还是查不到，需不需要联系USCIS?

谢谢！