are guidebooks really uful f
因为really fun, 是用副词really 来修饰形容词fun，fun在这里不再是名词了，所以用really。
重点词汇解释：
really 英[ˈri:əli] 美[ˈriəˌli, ˈrili]
adv. 实际上; 真，真正; 实在，果真; 事实上;
[例句]I'm very sorry. I really am.
我很抱歉。真的。
fun 英[fʌn] 美[fʌn]
n. 乐趣; 娱乐活动; 嬉戏，嬉闹; 有趣的事;
adj. 开心的; 使人愉快的;
vi. 嬉闹; 开玩笑;
[例句]This year promis to be terrifically good fun.
今年一定会非常有意思。
book 英[bʊk] 美[bʊk]
n. 书; 卷; 课本; 账簿;
vt. 预订;
vt. 登记; （向旅馆、饭店、戏院等） 预约; 立案（控告某人）; 订立演出契约;
[例句]His eighth book came out earlier this year and was an instant best-ller.
Science textbooks and technical and professional journals are usually made up of veral parts and contain various special features, many of which have a standard format.【B1】usually contain a large number of the parts; journals and【B2】contain many, but not all of them. Knowing where to look for information and【B3】to expect in a book can greatly increa your ability to u all the information there. Explanations of and practice
using some of the textbook parts and【B4】are covered in the even numbered lessons. The features in textbooks are【B5】into the following three categories. Front matter is the【B6】-numeral paginated ction at the front of most books. The text is the main body of the book. The【B7】matter compris the additional ctions at the back of most books.【B8】our discussion of the three ctions will deal mainly with textbooks, the practice provided will greatly【B9】your comprehension of scientific【B10】as well.
