Respuesta :

2. shall
3. a. may  b. can
4. shall
5. can
6. a. could, then the other a. shall 
7. a. may, then the other a.could
8. didn't need to 
9. could
10. needn't

2:will
3: 1.may 2.can
4:shall
5:can
6: 1.could 2.shall
7:may
8:didn't need to