1. couldn't
2. can
3. could
4. can't
5. can't
1. A hundred years ago we couldn't chat on the internet! 2.We can choose how we memorize things 3.My dog could run when it was young but it's too old now! 4.When I was two weeks old,I couldn't talk. 5.Elephants can't fly.
Объяснение:can-уметь can't-не уметь could-мог couldn't-не мог