i am in the bookstore now.i want to buy a story book and a comic book.look! i have found the books.they[6]interesting.however,the storybooks[7]expensive,but th

i am in the bookstore now.i want to buy a story book and a comic book.look! i have found the books.they[6]interesting.however,the storybooks[7]expensive,but the comic books are[8]
6. a.is b.does c.are d.do
7. a.be b.is c.am d.are
8. a.cheap b.more cheap c.cheaper d.the cheapest