什么是安全设备？

在某电子设备的生产中，需要使用100Ω的低值电阻器，设计要求其最大允许误差应在±0.1%以内。为此，对选用的高值电阻进行测量，以确定其电阻值是否满足预期的使用要求。测量方法是用一台数字多用表对被测电阻器的电阻进行直接测量。已知该数字多用表经检定合格并在有效期内，其测量电阻的技术指标如下：

最大允许误差为±(0.05%×读数+3×最低位数值)；

测量所用挡的满量程值为199.9Ω，最低位数值为0.01Ω；

当环境温度为(20±5)℃时，温度的影响可忽略。

在22℃时，实测10次，得到样本均值R=99.8Ω，S(R)=0.25Ω。

扩展不确定度为（）Ω，取包含因子k=2。

A．0.09

B．0.16

C．0.182

D．1.82

在一次同学聚会时，大家一见面就相互握手．有人统计了一下，大家一共握了45次手，参加这次聚会的同学共有（     ）人．

One girl decided to study judo（柔道）although she had lost her left arm in a car accident.

The girl began lessons with an old Japanese judo instructor. The girl was doing well. So she couldn’t understand why, after three months of training, the instructor had taught her only one move.

“Instructor,” the girl finally said, “Shuldn’t I be learning more moves?”

“This is the only move you know, but this is the only move you’ll ever need to know,” the instructor replied.

Not quite understanding, but believing in her teacher, the girl kept training.

Several months later, the instructor took the girl to her first tournament. Surprising herself, the girl easily won her first two matches. The third match proved to be more difficult, but after some time, her opponent became impatient and charged. The girl skillfully used her one move to win the match. Still amazed by her success, the girl was now in the finals.

This time, her opponent was bigger, stronger and more experienced. For a while, the girl appeared to be overmatched. Concerned that the girl might get hurt, the referee called a time-out. She was about to stop the match when the instructor intervened（干预）.

“No,” the instructor insisted, “Let her continue.”

Soon after the match restarted, her opponent made a serious mistake; she dropped her guard. Instantly, the girl used her move to pin her opponent. The girl had won the match and the tournament. She was the champion.

One the way home, the girl and her teacher reviewed every move in each and every match. Then the girl gathered the courage to ask what was really on her mind.

“Instructor, how did I win the tournament with only one move?”

“You won for two reasons,” the teacher answered. “First, you’ve almost mastered one of the most difficult throws in all of judo. Second, the only known defense for that move is for your opponent to grab your Left arm.”

The girl’s biggest weakness had become her biggest strength.

小题1:What can we learn about the girl?

A．She was disabled in an accident.

B．She disliked judo training.

C．She learnt several moves.

D．She won the first two matches hard.小题2:The underlined word “overmatched” probably means         .

A．impatient

B．depressed

C．defeated

D．trapped小题3:The girl won the championship because of          .

A．her bravery

B．her skills

C．her tricks

D．her strength小题4:Which of the following is probably the best title of the story?

A．The Story of a Girl.

B．A Disabled Girl.

C．Defense Matters.

D．Weakness Becomes Strengh.

第一台电子计算机是1946年在美国研制的，该机的英文缩写名是______。

A．ENIAC

B．EDVAC

C．EDSAC

D．MARK-II

需要载体帮助但不消耗能量的转运方式是（）

A.溶解扩散

B.限制扩散（微孔途径）

C.主动转运

D.易化扩散

E.胞饮作用