Sure, here are the completed sentences with the correct form of the phrasal verbs:

1. They planned to **go out** and celebrate their anniversary at a fancy restaurant.
2. The children walked into the park and **looked around**, trying to find a suitable spot to have a picnic.
3. The doctor advised me to **cut down on** my caffeine intake to reduce my anxiety.
4. He **took care of** the household chores while his wife was away on a business trip.
5. The memories of that trip always **come back** to me when I see these old photographs.
6. We **ran out of** gas on our road trip, so we had to stop at a nearby gas station.
7. The scientist did several experiments to **find out** the effects of the new drug.
8. It is important to **pass down** family traditions from one generation to the next.
9. Last month, our team **set up** a charity event to support local businesses.
10. Despite their initial differences, the two roommates eventually **got on with** each other and became good friends.

For Exercise 11:

1. By eliminating unnecessary steps, we can **shorten** the process and save valuable time.
2. A candle not only provides light but also creates a pleasant **fragrance** when it is burnt.
3. **Famous** local festivals in the city attract millions of visitors from all around the world every year.