问答题

【参考答案】

许多年前，科学家们就已经知道人们需要维生素D。维生素D帮助身体吸收钙质，从而促进骨骼和牙齿的生长并使其坚固。研究显示，缺......

(↓↓↓ 点击下方‘点击查看答案’看完整答案、解析 ↓↓↓)
<上一题 目录 下一题>
热门 试题

填空题
And in all states
单项选择题
A. Try another approach. B. Give yourself some time for sleeping. C. Keep on learning and practicing. D. Reward yourself from time to time.
A. Try another approach.
B. Give yourself some time for sleeping.
C. Keep on learning and practicing.
D. Reward yourself from time to time.
相关试题