But underneath the jacket is this case, and that's the cover underneath the book, the jacket, and there's an ad that offers a free 30-day risk-free trial for a blue whale.
书的封套下面是这个盒子 那是书下面的封面 封套 上面是一则广告 30 天免费试养蓝鲸 30 天免费试养蓝鲸