Sure! Here are the answers for the blanks:

I. Look at the pictures and complete the blanks:
1. waterfall
2. snow
3. road
4. animal
5. desert
6. scissors
7. backpack
8. compass
9. flashlight
10. banana

II. Complete the following phrases with the given words:
1. swim in the **river**.
2. Explore the **cave**.
3. Have a **painkiller**.
4. Sleep in a **tent**.
5. Lather with **sun cream**.
6. Set up a **tent**.
7. Climb up the **mountain**.
8. Walk with **walking boots**.
9. Wear a **sun hat**.
10. Eat **seafood**.
11. Cut with **scissors**.
12. Call with a **mobile phone**.

III. Put "must" or "mustn't" into each gap:
1. You **must** tidy up your room.
2. It’s late. You **mustn't** make so much noise.
3. You **mustn't** smoke.
4. We **must** be home by 9 o’clock. The film starts at 9:15.
5. You **must** do your homework.
6. I **must** finish this essay today. It has to be handed in by tomorrow.
7. Passengers **must** talk to the driver whilst the bus is in motion.
8. This is a dangerous tour. Children **mustn't** be accompanied by an adult.
9. You **must**...
10. You **mustn't**...

Let me know if you need more help!