Exercise 2 :
1.How long have you known Gerry ?
2.You look dirty. What have you been doing all day?
3.How many times has Charles visited New York?
4.She has been learning French words for hours, but she still doesn't remember all of them.
5.The children have been watching videos for two hours.
6.Has he been studying hard today?
7.Sorry, I'm late. Have you been waiting for long?
8.We haven't seen Lisa recently.
9.He has been writing his essay all day, but he hasn't finished yet.