阅读下面短文，根据所读内容，在文章后小题的空格里填入一个最恰当的单词。
Blood donation, also called blood banking, is a wonderful thing to do. It is an easy and direct way of making a contribution to social work and having a big effect on the community. It helps to save lives and helps those who are in need of blood because of bad conditions or the heavy loss of blood during operations or in accidents.

You are able to give or donate blood every three or four months. The doctors say it is not bad for your health. It is such a beautiful way of making a huge difference to someone’s life and you can always be proud of it if you make a valuable contribution to society. Blood donation is not a big problem, but you need to keep a few points in mind.
Before donating blood, make sure that the ferrum(铁) level in your body is high enough and for that you should take a healthy diet. Do not go for blood donation with an empty stomach. You should follow the correct process so that everything goes well. After having a balanced diet you will feel strong and comfortable to donate blood. You will not feel weak at the same time.
For required hemoglobin(血红蛋白) in your body, drink lots of juice and other drinks. Fruit juice, such as apple juice is very good for increasing the blood level in your body.
For a good blood flow(血流) in your body, drink at least 6-7 glasses of water every day. Completely avoid taking alcohol or caffeine a day before and after giving blood. Do not smoke cigarettes(烟) half an hour before giving blood.
When you are going for blood donation, be relaxed, which helps keep the right blood pressure(血压). During the blood donation activity, you can breathe deeply and try to calm yourself down. Don’t take part in some other activities.
When you donate blood, you are making the effort to save someone’s life. Blood donation is a very simple and fast process, but you need to take care of yourself after donating blood. Proper care helps to reduce side effects. The following are a few tips that will help you out.
Take a rest for 15 minutes after completion of the donation. It helps you to feel relaxed and energetic.
Eat something and drink juice before leaving the blood donation center. Make sure that you have meals after donating blood. Smoking should be prevented for one hour after the process. Don’t join in some activities at once, for example, driving.
Finally, be proud of yourself because you have done a great thing in helping to save someone’s life. Blood donation is a very important activity.

Title	Blood donation— an important activity
The           of blood donation	Making contributions to     work and the community. Helping those people who suffer the        of blood.
Before the donation	Take a healthy diet for a         ferrum level. Drink fruit juice for enough hemoglobin. Drink at least 6-7 glasses of water a day for a good blood flow. Avoid taking alcohol and      cigarettes. Never take        in other activities.
During the donation	Relax and take a       breath.
After the donation	Take a rest. Don’t forget meals. Don’t smoke          one hour later after the process. Never join in some activities         . Giving yourself a sense of        of it after making a valuable contribution to society.