This a two part sweater: from the back it looks like two layers - one longer then the other, and from the front it looks like 你 are wearing a strapless 最佳, 返回页首 and a sweater on 最佳, 返回页首 of it . link
照片
sweater
最佳, 返回页首
This Teen Fashion 照片 contains
羊毛衣 and 羊毛衫.
There might also be
套头毛衣, 套衫, 套头衫, 下滑, 毛衣, and 跳线.