Watch this video about the inner life of a cell

http://aimediaserver4.com/studiodaily/videoplayer/?src=ai4/harvard/harvard.swf&width=640&height=520
http://www.centreofthecell.org/interactives/exploreacell/index.php
Now here is your challenge: this webquest .Click on the following link to start working!!!
http://mrscienceut.net/CellWebquest.htm

Talking about the past

 Practice the past  tense of the verb "BE" in the following links:

 exercise1,exercise2,exercise 3,exercise4,exercise 5

Now practice the past simple of the rest of the  verbs .

exercise1,exercise2,exercise3,exercise4,exercise5,exercise6