True or fasle?
A. The present perfect simple is used to talk about an action that has finished but has an effect in the present.
B. The present perfect simple is used to talk about an action or state that started in the past and continues to the present.
C. The past simple is used to talk about experiences that have or haven't happened at an unspecified time in the past.

Sentences.
1. The Internet HAS BECOME more and more popular.
2. Ninety per cent of us HAVE SENT or received an email.
3. Fifteen years ago very few people USED the Internet.
4. In the past 15 years the Internet HAS OPENED UP a whole new world to us.