题目

具有100个碱基对的一个DNA分子片段，内含60个腺嘌呤，如果连续复制2次，则需要游离的鸟嘌呤脱氧核苷酸（   ）个 A．60                B． 80                C． 120               D． 180 答案：CI’m punctual(守时的) in my work life, but not in my personal life. However, it’s OK in my country. We, Brazilians, are always late: if the party is at 8, everyone shows up at 10 and everyone, including the host, is happy that we are on time. Cheers!Lisa Rio de Janeiro, BrazilI’m a Japanese working in Colombia. It is good manners to arrive a little late for a party in Colombia, which I have never understood. I always try to be early for everything, or I consider it impolite.Mike Tokyo, JapanOf course! My friends and I all believe that showing up late for an appointment or class is an insult(冒犯) to the person(s) we are meeting. It seems to say, “My time is more important than yours.”Vera Lausanne, SwitzerlandNot only am I “punctual”, but I am always early for most events in my life. The secret is (and it really works!): I keep all the clocks (except my computer) in my life 10 minutes fast!Wang Cai Shenzhen, ChinaFor an appointment, I always make sure I’m on time. Once I had a friend who was always late for every meeting. If we made it at 9 and it was a 45-minute trip for her, then she would arrive at 9:45. I liked her a lot, but could not stand the unpunctuality.Bud Berlin, Germany1.If you attend a Brazilian’s party and are 2 hours late, the host will ______________.A. ask you why B. think you are impoliteC. think it doesn’t matter D. ask you to drink with him2.Where is it OK to arrive a little late for a party?A. In Japan. B. In Colombia. C. In Germany. D. In Switzerland.3.Suppose it’s ten o’clock in the morning. What does Wang Cai’s watch say?A. 9:50 am. B. 10:00 am. C. 10:10 am D. 10:20 am.4.Who was always late for every meeting?A. Vera B. Vera’s friend C. Bud D. Bud’s friend5.The material is probably from_____________.A. a website B. guidebook C. a school notice D. a science magazine