What do you call this in English?—It’s a stamp. It is used ______ sending. [ ]

I often have chicken and fruit ______dinner.[ ]

Some scientists think that it may take ______ years to make robots look like people, and do the same things as us.

Many famous movie stars attended the news briefing (新闻发布会), Jackie Chan and Jet Li. [ ]

We have two foreign teachers here. One is from England, and ______ is from America.