Fill the gaps with the modals can and must or their

Fill the gaps with the modals can and must or their equivalents. In some sentences more than one variant is possible.
1nbsp; nbsp; I go to the swimming pool three times a week. 1 hope I ... swim quite well by next summer.
2nbsp; nbsp; Do you know that cats ... see very well in the dark?
3nbsp; nbsp; Some animals ... do without food for a very long time. Snakes, for example____survive the whole winter without eating.
4nbsp; nbsp; When I was a little girl, I ... do acrobatic feats (трюки), but now I cant.
5nbsp; nbsp; There are no tickets for our flight so we ... go by train.
6nbsp; nbsp; If there is not going to be any information about those passengers till tomorrow morning, we ... call the police.