2016届高三英语（北师大版）一轮复习能力自评：Unit 23 Society 24-3_高考复习指南

2016届高三英语（北师大版）一轮复习能力自评：Unit 23 Society 24-3

　　18. A　参见上题解析。

　　19. C　由最后一段可知，那晚的经历改变(changed)了作者的生活。20. D　这次经历让作者以后在抱怨(complain)缺少什么东西前三思。

　　Ⅱ.阅读理解

　　Every year, World Blood Donor Day is celebrated by blood services worldwide on 14 June, the birthday of Nobel Prize winner Karl Landsteiner, the man who discovered the ABO blood group system. If you have ever thought of becoming a blood donor, just register to do it. And you should never worry about the donation.

　　Just under a pint(around 470ml) of blood is taken at one sitting. This amounts to no more than 13 percent of your total blood volume, and is quickly replaced by your body.

　　It may come as a surprise, but whole blood is only rarely used. Different blood components are used to treat a range of conditions. None goes to waste. Red blood cells are frequently used to replace heavy blood loss after an accident, surgery or childbirth. White blood cells and antibodies are used to help people fight infections if their immune system doesn’t appear to be responding to antibiotics(抗生素). Plasma(血浆), the straw coloured fluid which carries the blood cells and contains proteins is used to treat burned patients.

　　First time donors should be aged between 17 and 65, weigh at least 50kg and in good health. If you have donated before, you can start being a donor again up to your 70th birthday. There is no age limit for donors who have donated in the last two years. Although most people are able to give blood, some are asked not to be donors. This is usually because it poses a health risk to the donor or the person concerned may be at a higher risk of having come into contact with an infectious disease. Pregnant women or those who have had a baby in the last 9 months should not donate blood.