重点讲解：
1. be susceptible to 易受(伤)的；
Some of these plants are more susceptible to frost damage than others.
这些植物中有一些较其他的易受霜冻危害DGC&JFItF~G[!.S1qb_。
2. be exposed to 使暴露于（险境）；使遭受（危险或不快）；
They were exposed to radioactive fallout during nuclear weapons tests.
在核武器试验中他们暴露在放射性尘埃之下BL|+]8Az4llG@Xssj[WZ。
3. be resistant to 有抵抗力的；不受…损害的；
Cotton is more resistant to being squashed and polyester is more resilient.
棉布更抗压，而涤纶更有弹性iPyhozIzrD]+A%^Il。
4. ball up （使）成球状（或团块）；
She balled the handkerchief up and threw it at his feet.
她把手绢揉成一团，丢在了他的脚边LHF9pjASCruh。