Psychology homework help

1)  In the article on cigarette smoking on college campuses by Lee, Ranney, and Goldstein (2013):

Lee, J. G., Ranney, L. M., & Goldstein, A. O. (2013). Cigarette butts near building entrances: what is the impact of smoke-free college campus policies?. Tobacco Control, 22(2), 107-112.

what is the explanatory variable and what is the criterion variable?

2)  For each of the following experiments below, identify:

a) The independent variable

b) The dependent variable

c) The extraneous variable, and 

d) How might the experimenter control for each extraneous variable?

Experiment #1:  A developmental psychologists want to know if exposing children to public television improves their reading skills.  She also knows that students who attend charter schools have higher reading scores than those that attend public schools.

Experiment #2:  A forensic psychologists wants to know whether exposing a person to a clip from a TV show like CSI or Forensic Files would change their attitudes about DNA evidence.  He also knows that some people have never seen these shows before and some people watch it crime dramas like CSI every week.  

Experiment #3:  A clinical psychologist wants to know if a new anti-depressant drug will cause less suicidal thoughts than other anti-depressant drugs currently on the market.  They also know that people who abuse the drug crystal meth have more suicidal thoughts than other people do.