Which is why it's so hard to predict bestsellers, why you can't judge a book by its cover.

这就是为何预测畅销书很难，为何你们不能根据一本书的封面来对它作出评价。

youdao

We are professional produce animal glue which used for the high quality gift box, hard book cover, file and so on. These two shapes for the glue, one is jelly and another one is powder.

我们啫喱胶用于带有加温装置的机器，由于含水量很低，可以有效防止产品出现变形、起泡、发霉等不良现象，是制作高档礼品盒、精装书籍封面等产品的必用胶。

youdao

The Friends: Complete Series Blu-ray box set is presented in highly collectible new packaging consisting of a lenticular box cover, a hard-cover book that holds 21 Blu-ray discs, plus a 32-page episode guide.

ENGADGET: Friends: The Complete Series Blu-ray set arrives November 13th for just under three bills

Another thing I want is a book with a really nice hard-bound cover.

FORBES: Foldable iPads, Paper eBooks and Holographic Movies: The Best List of 2010