dress做连衣裙是可数名词。做衣服讲是不可数名词。N-COUNT 连衣裙A dress is a piece of clothing worn by a woman or girl. It covers her body and part of her legs. She was wearing a black dress.她穿一条黑色连衣裙。N-UNCOUNT 衣服You can refer to clothes worn by men or women as dress .He's usually smart in his dress.他通常穿得很精神。

　　连衣裙skirt是可数的

　　dress连衣裙，可数名词，复数形式dresses