This is an useful book .You had better read it carefully 此句有一个错误 请找出来十万火急 八百里加急啊

This is an useful tool.这个句子哪里错了? 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 is () useful story book.. This is quite a useful book .解释一下quite为什么放在 a前面,useful是什么意思,为什么不定冠词不使用an? A horse is ( ) useful animal.A.an B.a C.the D.this This is ___ useful dictionary .选择：A.an B.a C.the D./ This is so useful an information that all of us believe it's very important. This is an useful book.You'd better read it carefully.修改病句 This is an useful book .You must read it carefully .哪里错了? This is a ( ) useful advice A a B an C the D 应选哪一个急死了 I think this is ____ useful dictionary.A.very a B.very an C.quite a D.quite an This is _____ that all of us believe it’s very important.(2005年广州) A.such useful informationB.so useful an information C.so useful information D.such a useful information 给点建议 This is an empty bottle, but it is ___ useful one. 为什么填a 不填the This is useful work改为否定句 This is useful work改为一般疑问句 This is ( )empty bottle.But it is ( )useful one.A a ;a B an; a C an;the D a;an this si an useful tool 错在哪? This is _____ useful book.I read _____ book every day.[ ]A.an,/ B.an,the C.a,the D.a,a