We all need Vitamin（维生素）D because it helps to build and keep strong bones.A lack of it can lead to some bone diseases.As studies show,sunlight is great for making Vitamin D.When you're outdoors,your body will create the Vitamin D you need from direct sunlight on your skin.
In order to get enough Vitamin D，you should get 10-30 minutes of sunlight at a time,several times a week.However,people with darker skin may need a little more time than this.Besides,your exposure（暴露）time in the sunlight should depend on how sensitive（敏感）your skin is to sunlight.Too much sunlight can be dangerous,for it may cause some bad results,including sunburn,eye damage,and skin problems.If you have to stay in the sunlight for a long time,you should be careful not to let sunlight hurt your skin,so take care to protect your skin with sunscreen before it starts to turn red.
In a word,your ability to make Vitamin D from sunlight depends on the time of day,your skin color,where you live and so on.Keep those in mind when you go out for Vitamin D from sunlight.



Why do people need Vitamin D according to Paragraph 1？ ______

A. To keep their hair healthy.
B. To make their teeth white.
C. To make their faces pretty.
D. To keep their bones strong.

We can infer that our body creates Vitamin D by ______ .

A. doing some exercise
B. losing much weight
C. staying in the sunlight
D. walking in the moonlight

What does the underlined word "sunscreen" in Paragraph 2 probably mean？ ______

A. 防晒
B. 防水服
C. 防尘罩
D. 防腐剂

Where is the text probably taken from？ ______

A. A story book.
B. A telephone book.
C. A health magazine.
D. A music magazine.