Statistics help, please?

For the following three examples, state:

a) The null hypothesis

b) The alternative hypothesis

c) A description of what a type I error looks like in this context

d) A description of what a type II error looks like in this context

1. A highway patrolman issues a blood alcohol test on a driver

2. A public school internet filter blocks suspected pornographic sites from being downloaded by students

3. A ban is proposed on a video game because of data that seems to show that it causes violence in teenagers

Thank you for your help, I really appreciate it