April 20th ,2013,earthquake hit Ya an.A.an B.a C,不填 D.the

问题描述:

April 20th ,2013,earthquake hit Ya an.A.an B.a C,不填 D.the

应该选 an
这里是泛指 “一场地震”.
on April 20th ,2013,【an 】earthquake hit Ya an