1.reason why we need CD at the back of this book.

-because it's there

-help me revise the pronounciation of these words in the text book

-help me preview the chapters that teacher will teach next week

2.Roman Numbers:

code name        Decimal:4.9 

I:1                   EX.iii→3

v:5                       IV→4

x:10                     VIII→8

L:50                     IX→9

C:100                  XIII→14

D:500                  MMXIV→2014

M:1000                XVIII→18