科学界的共识是,人的皮肤可以通过日晒产生维生素D.而产生的数量并不固定,这取决于人所在地,皮肤的状况,年龄以及其他的因素.
Scientists have long known that vitamin D is a vital nutrient that the skin produces when hit by sunlight. The amount varies, depending on where the person lives, skin pigment, age and other factors.
随着藻类的运动，光亮和黑暗交替出现，把碳固定住并不断增加其数量，这可能是通过促成只在晚上进行的化学反应而产生的。
The constant shift between light and darkness as the algal cells circulate increases the amount of carbon that they fix, probably by promoting chemical reactions that occur naturally only at night.
应用推荐