Here are the answers to the exercises:
- Maria got some bad news last week. She has been sad since she got the bad news.
- I started school when I was five years old. I have been at school since I was five years old.
- I have changed my job three times this year.
- The weather was hot and dry for many weeks. But two days ago it rained.
- Tom broke his leg five days ago. He's in hospital. He has been in hospital since he broke his leg.
- Are you going to finish your work before you go to bed? — I have already finished it. I finished my work two hours ago.
Choose the correct preposition with the phrasal verb to turn.
- Please, turn on the radio. I want to listen to music.
- I'm exhausted. I think I'll turn in.
- At night Fiona turns into an ogre.
- Turn off the lights. I'm sleepy.