Could, mustn´t oder needn´t exercises?

Setze could, mustnīt oder neednīt ein.

1 We forget our maps! They're important.
2 We take the bus. We can go by Tube.
3 you drive me to Big Ben, please?
4 It's red. You cross the road!
5 We go to the London Eye. I went there last year.
6 Ben, you please sit next to Jake?
7 You forget to visit London Eye. It's great!
8 The sign says you use your mobile!
9 You buy me a ticket. I have one.
10 I send you a text message but my battery is dead.