Choose the correct options

1. collect
   [-able|-ible|-ent]
2. work
   [-able|-ible|-ent]
3. invest
   [-ive|-ible|-ent]
4. differ
   [-able|-ible|-ent]
5. teach
   [-able|-ible|-ent]
6. prevent
   [-al|-able|-ent]
7. drink
   [-able|-ible|-ent]
8. refer
   [-ese|-ible|-ent]