精选优质文档-倾情为你奉上I.单项选择（每题1分，共15分）( )1.This is _useful book. I want to buy it. A. an B. a C. the D.( )2. -Is that a blue pen? -_, it is a yellow pen. A. Yes, it is B. Yes, that is C. No, it isnt D. No, that isnt( )3.Marys birthday party is _ January 1 st. A. in B. on C. at D. to( )4.There are _ months in a year. The _month is September. A
