Here are the completed sentences with the suitable verbs:

1. I am going on a diet **to lose** weight.
2. The President has a team of bodyguard **to protect** him.
3. Mike hid behind the tree **to avoid** being seen by his friends.
4. We took off our boots **to keep** the floor dirty. (Note: The correct verb "keep" is not on the list, but "reduce" or "avoid" could fit if rephrased.)
5. We wrote Betty’s name on the calendar **to remember** her birthday.
6. The government took these measures **to reduce** crime.
7. The staff are working at weekends **to complete** the project in time.
8. She gave up her job **to take** care of her mother.
9. I shut the door quietly **to avoid** waking up the baby.
10. She took a bus **to avoid** being late.
11. He turned on the radio **to listen** to the news.
12. After dinner we drove to the top of a hill outside the city **to watch** the sunset. (Note: The correct verb "watch" is not on the list, but "admire" could fit if rephrased.)
13. Leave early **to catch** the bus. (Note: The correct verb "catch" is not on the list, but "take" might be a substitute.)
14. I carried the knife carefully **to avoid** cutting myself.
15. We went to the countryside **to avoid** being disturbed by the noise of the city.

Please adjust any verbs that may not fit perfectly with your original instructions.