This is ______ useful book. A. a B. an C. the D/This is ______ useful book.A. a B. an C. the D/要解释

This area is protected=This is a _____ ______. This is my ______ (parent) room. This blue bag is ______ my mother. This room is ______(fill) of children. this apple is ______ your grandmother. This lesson is too hard ______ him This is the factory ______ he works ___ ______ is your mother this year? This is a very interesting film.(改为感叹句)______ ______ interesting film this is! I think this programme is boring的同义句I ______ think this programme is ______ This girl is from the USA.She is ______(America) China is a_______country.______!This prerent is for me. This is a ruler.______ is black.应填什么 this tree is 50 years old that tree is 90 years =this tree_____ ______ _______ ______ ____ ______ This book is his.(改同义句)This book _______ ______ ______. 这部电影确实令人兴奋.This is movie ______ ______ ______. This is a new bus .改复数 ______ ______ new ______. This is his mother.(对his mother提问） ______ ______ ______?