什么叫刚性路面？

差动监视元件的作用是1）保证继电器的安全性，避免某一元件故障而产生的误动作；2）可限制保护的灵敏度（如CT开路），而不改变主差动的制动特性。

C

Sports is not only physically challenging, but it can also mentally challenging. Criticism（批评）from coaches(trainers), parents, and other teammates, as well as pressure to win can create too much anxiety or stress for young athletes. Stress can be physical, emotional, or psychological, and research has showed that it can lead to burnout. Burnout has been described as dropping or quitting of an activity that was at one time enjoyable.

The early years of development are critical years for learning about oneself. The sport setting is one where valuable experiences can take place. Young athletes can, for example, learn how to cooperate with others, make friends, and gain other social skills that will be used throughout their lives. Coaches and parents should be aware(realize), at all times, that their feedback（反馈）to youngsters can greatly affect their children. Youngsters many take their parents’ and coaches’ criticisms to heart and find a flaw（缺陷） in themselves.

Coaches and parents should also be cautious(careful) that youth sport participation does not become work for children. The outcome of the game should not be more important than the process of learning the sport and other life lessons. In today’s youth sport setting, young athletes may be worrying more about who will win instead of enjoying themselves and the sport. Following a game, many parents and coaches focus on(pay more attention to) the outcome and find fault with youngsters’ performances. Positive reinforcement should be provided in spite of the outcome. Research shows that positive reinforcement motivates and has a greater effect on learning than criticism. Again, criticism can create high levels of stress(pressure), which can lead to burnout.

64．According to the passage sport is positive for young people in that         .

A．it can help them learn more about society

B．it teaches them how to set realistic goals for themselves

C．it enables them to find flaws in themselves

D．it can provide them with valuable experiences

65．Many coaches and parents are in the habit of criticizing young athletes         .

A．without realizing criticism may destroy their self-confidence

B．in order to make them remember life’s lessons

C．believing that criticism is beneficial for their early development

D．so as to put more pressure on them

66．According to the passage parents and coaches should         .

A．help children to win every game

B．pay more attention to letting children enjoy sports

C．enable children to understand the positive aspect of sports

D．train children to deal with stress

67．The author’s purpose in writing the passage is         .

A．to persuade young children not to worry about criticism

B．to emphasize the importance of positive reinforcement to children

C．to discuss the skill of combing criticism with encouragement

D．to teach young athletes how to avoid burnout

心室肌细胞动作电位平台期的离子跨膜流动是（）。

A.Na⁺内流，Cl^﹣外流

B.Na⁺内流，K⁺外流

C.Na⁺内流，Cl^﹣内流

D.Ca²⁺内流，K⁺外流

E.K⁺内流，Ca²⁺外流

AD166显影仓中碳粉入口搅拌疏导条，可以防止循环供给部分的碳粉堵塞。

质量监督人员的监督范围包括（）。

A.监督质量管理主体

B.上班时间

C.监督维修质量

D.下班时间

E.工效