如图所示，人通过跨在光滑滑轮上的细绳拉一物体静止。当人向后跨了一步后，人与重物再次保

光盘是外存储器的一种。

保护生物多样性意义重大，其最为有效的措施是（　　）

A．在公园里放养

B．建立自然保护区

C．与其他国家交换

D．私人收养

The repairman told me, “No charge Professor Pan! We’re friends．” “I’d rather pay,” I replied．“If it’s free, I can’t afford it!”

Chinese often refuse payment for professional services, insisting, "We’re friends now!" But then they show up later to ask me to tutor them in English, or get them into an American university, and I wish I’d have just paid the 30 yuan I owed them in the first place!

According to the Americans, "There’s no free lunch," meaning that there’s a price for everything, and I’m always looking around to figure out what this means．Many of our neighbours have given us fruit or flowers or costly teas, never asking anything in return．For years, a bicycle repairman has repeatedly refused to let me pay him．"Wait until you have something major to fix! "he insists．

I mentioned to a peasant friend that I wished I had a stone mill to grind(磨)flour for bread．A month later he showed up with a beautiful mill that he’d had his uncle in the countryside carve from a solid block of granite(花岗石)．

Chinese generosity(慷慨)is a real education for Americans like me, who would rather avoid social entanglements (纠纷) and just hand over the money．But cash can’t compensate(补偿)for the greatest gift--friendship．

When an American saw some of my friends sitting on bamboo stools under the trees, sipping(呷)tea, he said, "They  must have nothing better to do．""Actually, "I said, "they are professors, with plenty to do．But probably you’re right in saying that, at this moment, they have nothing better to do．And neither do I!" And I joined the group．We chatted about tea and Chinese cooking and how much my boys have grown since we arrived．One man said, "They were pocket-sized when you came here．Now

they’re taller than you．How time flies!"

How life flies．And Chinese are smart enough to share what they know they cannot keep．They freely give of their time, never too busy to help a friend．And they are teaching me, slowly, to both give and receive．So the next time someone says, "No charge．We’re friends! " I will thank them heartily．But if they show up later asking me to tutor them in English, I’ll make sure they tutor my son in Chinese as well, because there’s still no free lunch．

64．The author insisted on paying repairman while he was offered free repairs because he     .

A．was an honest man

B．didn’t know the repairman

C．thought it natural to pay for others’ service

D．didn’t want to help others in return

65．Generally, the author thinks that Chinese are _________．

A．generous and always ready to help their friends

B．good at exchange of equal values

C．free enough to drink tea and chat with their friends

D．helpful but don’t treasure time

66．The best title of the passage should be “       ”.

A．Learn to Both Give And Receive    B．A Good Lesson from Chinese

C．True Help or Not                   D．Still No Free Lunch

67．Which of the following is TRUE?

A．The Chinese would rather not take the money to avoid problems in social communication.

B．When a peasant knew the author needed a mill, he made one for the author himself.

C．The author thinks that Chinese are wise enough to enjoy the limited life.

D．The author thinks little of Chinese way of life.

报检入境废物时，除提供合同、发票、箱单、提单之外，还应提供国家质检总局签发的进口废物批准证书和经认可的检验检疫机构签发的装船前检验证书。（）

某化合物在阳光的照射下会发生一些变化，其中的一些元素会改变自己原有的形态，以另外一种形态存在。为了确定这些改变存在形态的元素，科学家通过三个实验获得了如下信息：
试验一：或者是A元素，或者是B元素
试验二：或者不是B元素，或者不是C元素
试验三：如果不是C元素，就不是B元素
根据上述三个实验，以下哪项一定为真( )

A．这种元素是A元素
B．这种元素是B元素
C．这种元素是C元素
D．这种元素不是A元素