Modals
1) Is your meeting this afternoon important? Yes, and I ...
be late. Needn't/mustn't/haven't got to.
2) ...your brother play the guitar? May/Can/Shall
3) Do you think I .... give my mother a ring?
Should/ought/must
4) What's your hotel room like? It's lovely and you ....
see the sea from my balcony. Need/might/can
Key
1) Must not
2) Can
3) Should
4) Can
5) Could
References
http://www.englisch-hilfen.de/en/grammar/hilfsverben2.htm
http://www.englishpage.com/modals/modalintro.html
http://www.englishclub.com/grammar/verbs-modals.htm
http://mimosa.pntic.mec.es/~jherre23/
Thanks for listening!