阅读下列句子，体会黑体部分的用法
1．Following Jane's way of studying chimps，our group are all going to visit them in the forest.
2．Watching a family of chimps wake up is our first activity of the day.
3．Everybody sits and waits in the shade of the trees while the family begins to wake up and move off.
4．Jane warns us that our group is going to be very tired and dirty by the afternoon and she is right.
