an eiephant is-useful animal的横线应填什么?A.a B.an C.the D./

an eiephant is-useful animal的横线应填什么?A.a B.an C.the D./ ___ elephant is ___ useful animal.A.An;an B.An;a C.Thn;an D. This is a ( ) useful advice A a B an C the D 应选哪一个 an useful animal?还是a useful animal? 改错：A fox is an useful animal. This is ______ useful book. A. a B. an C. the D/ This is ___ useful dictionary .选择：A.an B.a C.the D./ The elephant is _____ useful animal to human beings.A.a B.an English is 什么 useful language in 什么world A.an,the B.a,the C. ___apple is ______fruit A.不填;a B.the;a C.an ;a D.an;/ 请问选什么? _television is more useful than _radio.A A,a B An,an C The,t 几道简单的英语单项it‘s such useful lanuage!A.a B.an C.the D.不填-When w