大学英语听力练习：吃蔬菜的正确时间

Timing Your Vegetables Right

Veggie Insect Repellent When a vegetable is growing, it protects itself from insects by producing chemical nutrients that make it taste bad or seem repellant to predators. Some of these nutrients—in particular phytochemicals—have been shown to fight cancer in people. What’s more, many vegetables are able to anticipate when insects will attack, and will ramp up its defenses accordingly.

Light Exposure Even after vegetables are harvested and they’re no longer fighting insects, these garden wonders can still be made to produce more nutrients at certain times. This is done by varying a vegetable’s light exposure to simulate the experience of night turning into day. Studies have shown that vegetables stored this way produce more phytochemicals during the light cycle.

So eating vegetables during this golden period means you’re getting more nutritional value!

It’s not yet clear how people might be able to activate these nutrition-packed properties at home. Perhaps simply storing veggies in the dark and then subjecting them to a flash of light is enough to trigger the process. Or it could be more complex. In any case, more research could help us find ways to maximize vegetables’ nutritional benefits. 吃蔬菜的正确时间

蔬菜杀虫剂

蔬菜在生长的过程中会产生化学养分，使其口感变差或让捕食者排斥，以此来保护自己免受虫害。这其中的一些化学养分，特别是植物素，已经被证明可以用于人类抵抗癌症。并且，许多蔬菜都能够提前预见昆虫的进攻，并相应地增加自身防御力。

曝光量

即便蔬菜已经丰收，无需再抵抗昆虫，这些菜园中的奇迹依旧能在某些时候产生较多的营养素。方法就是通过改变蔬菜的光照量来制造出昼夜交替的效果。研究表明这种方式下储存的蔬菜会在光照周期中产生更多的植物素。

所以在这段黄金时间吃蔬菜意味着你能获得更多的营养价值！

至于人们如何能在家就激活这些储存的营养素，还不甚清楚。也许只是简单地将蔬菜储存在暗处再给予它们一闪光亮就足以触发这一过程。或者还会更复杂。无论如何，更多的研究会帮助我们找到使蔬菜营养价值最大化的方法。