Can or Could in the Present Simple

CAN or COULD?

In the Present Simple, CAN is used for Tendency/Ability while COULD is used for Possibility/(Un)certainty

1. The internet _______________ be a dangerous place for children to visit.
2. I am not sure which airport we are flying from. It ______________ be Heathrow.
3. Women ______________ often get annoyed if you tell them that they look old.
4. Losing your job ___________________ have a devastating effect on your life.
5. They definitely live on this street but I am not sure about the number. It _____________ be 14 or it ________________ be 16.
6. I really like my new boyfriend. He ________________ be the man I end up marrying.
7. Smoking ________________ cause serious harm to your health.
8.  English grammar _____________ be so annoying.
9. I wish I ______________fly.