Which sentence is punctuated correctly? a. most people in brazil speak portuguese yet others speak polish and german. b. raisins are dried grapes, but, they have a burst of sweetness when you eat them. c. the snow is piling up, and the plows are unable to clear the roads. d. a tornado is a violent swirling column of air that touches earth and, a water spout is an intense column of air over water.

i don't see any questions on your profile, currently, but i'd be happy to try and with any problems that you have, so long as i understand the problem myself.

- "the basic difference between keywords and subjects is that subjects (or "subject headings") have been predetermined, while keywords have not. a keyword is an easy place to start because you can use any word that seems to fit your search; this is called "natural language" searching."