英语语法分析

Paintings must have rigid stretchers so that the canvas will be taut, and the paint must not deteriorate, crack, or discolor.

画必须有坚硬的画架，这样画布才会绷紧，而且颜料不能变质、开裂或变色。

Nevertheless, researchers have discovered that a process long known to discolor and toughen foods may also contribute to age related impairment of both cells and tissues.

然而，研究人员发现，一个长期以来众所周知的使食物变色和变硬的过程也可能与年龄相关的细胞和组织损伤有关。

UV resistant - does not discolor in the sunlight.

抗紫外线——日光曝晒下不易褪色。