——your dress is so nice .---thanks.my mother( )it for me as

选择C不是说瞬间动词不能用现在完成时,而是不能和表示延续一段时间的短语连用如：for... , since, how long 等.瞬间动词也有完成时：My mother has bought it.
但是如果是：How long has she bought it. 或者 She has bought it for three days. 就错了.