阅读下列句子，体会黑体部分的用法
1．...I saw several young people enter the waiting area looking around curiously.
2．I stood for a minute watching them and then went to greet them.
3．She stepped back appearing surprised...
4．Then Akira Nagata from Japan came in smiling，together with George Cook from Canada.
5．When Darlene Coulon from France came dashing through the door...
