Complete the sentence using the verb in brackets in Present Simple Passive.
Example: is done

1) Cheese (make) from milk.
2) A cinema is a place where films (show).
3) In the United States, elections for President (hold) every four years.
4) There's no need to leave a tip. Service (include) in the bill.
5) You (invite) to the wedding. Will you go?
6) Many accidents (cause) by dangerous driving.