you u n't makekeun of it. you can't abuse it, because this water is whahawe a a.. e pyramid lakeke isishat we are. captioning made possible by the annenberg/cpb project captioningngerformrm byy the national captitiing institute, inc. [thinking] glucose...plus oxygen... equals...carbon dioxide plus water... hey, gina, what's up? and energy... pulmonary artery... coronary artery... teacher: i'd like to pass them back to you now. i'm very pleased with your work. ...two types of endoplasmic reticulum... 3:00 already? [girl's thoughts overlap] announcer: she's got the drive, the energy... the heart... and the talent. pre-med. announcer: but she wouldn't be here without your help. please support the united negro college fund. because a mind is a terrible thing to waste. >> mayor for the city and county of san francisco. >> tonight, san francisco has a new interim mayor. >> a few minutes ago, city administrator now interim mayor ed lee, emerged happy but humble. >> in 2011, a temporary or interim mayor was selected by the board of supervisors, what is an interim mayor? wh