英语字母表中的第四个字母;(学生成绩)丁
网络 丁; 密度; 第四
The ´b´ had been wrongly written as a ´d´.
b错写成d了。
Milk, oily fish and eggs all contain vitamin D.
牛奶、油性鱼类和鸡蛋全都含维他命D。
Lack of vitamin D is another factor to consider.
缺乏维生素D是另一个需要考虑的因素。
Vitamin D is necessary to aid the absorption of calcium from food.
从食物中吸取钙需靠维生素D的帮助。
This special form of vitamin D is naturally present in breast milk.
这种特殊形式的维生素D天然存在于母乳中。