Mustn't vs. Don't Have To

Help the quirky museum guide establish the rules for the new "Interactive Prehistory" exhibit! Select ALL the sentences that correctly use modal verbs based on their meaning.

- [x] You mustn't touch the authentic T-Rex skull, or security will chase you!
- [x] You don't have to wear the 3D glasses if they give you a headache.
- [ ] You don't have to climb on the priceless artifacts; it's strictly forbidden!
- [ ] You mustn't tip the tour guide, but it is always highly appreciated.

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The correct answers are **You mustn't touch the authentic T-Rex skull, or security will chase you!** and **You don't have to wear the 3D glasses if they give you a headache.**

> Use **mustn't** for strict prohibitions (things you are not allowed to do). 

> Use **don't have to** for a lack of obligation (things that are optional, meaning you can do them if you want, but it's not required). 

> 

> Climbing on artifacts is forbidden, so it should be "mustn't." Tipping is optional, so it should be "don't have to."
