http://www.tau.ac.il/~becker/course/secondary.htmland count (and give the names of) all the different folds listed there.
TATAGAGACATAGinstead of the one in the text (hint: first do the one in the book and then check the answer in the back of the book).
TGCCATATATGTGCCGGGGAG ACGGTATATACACGGCCCCTCinstead of the one in the text (hint: first do the one in the book and then check the answer in the back of the book).