预计在超车过程中与对面来车有会车可能时，应提前加速超越。

错牙合畸形主动治疗结束以后，为防止复发，保持已经取得的矫治效果，需要用保持器。保持器就是防止复发的机械性保持装置

标准的Hawley保持器的基本结构是（）

A.位于侧切牙和尖牙之间的双曲唇弓.焊接在唇弓远中的尖牙卡环和基托

B.一对磨牙卡环，双曲唇弓及基托

C.一对磨牙箭头卡环，焊接在卡环桥部的双曲唇弓及塑胶基托

D.基托以及包埋在牙弓两侧最后磨牙远中面基托内的长唇弓

E.邻间钩，包埋于牙列两侧最后磨牙远中面基托内的长唇弓

市场经济体制不是区别社会性质的范畴，因此，社会主义市场经济同资本主义市场经济没有本质的区别。
请结合所学知识加以评析。

XD-22A型低频信号发生器的“输出衰减”旋钮置于40dB时，调节“输出细调”旋钮使指示电压表的读数分别为1V、3V、5V，问实际输出电压为多少？若指示电压表指针始终指在5V处，而“输出衰减”旋钮分别置于20dB、40dB、60dB时，问实际输出电压为多少？

假设国内生产总值是5000，个人可支配收入是4100，政府预算赤字是200，消费是3800，贸易赤字是100（单位：万元），试计算：（1）储蓄；（2）投资；（3）政府支出。

The finding is contrary to the common belief that all people are motivated to alleviate negative moods, according to Jonathon Brown, a University of Washington psychologist.

(46) “Many people with low self-esteem believe sadness is part of life and that you shouldn’t try to get rid of it, while people with high self-esteem believe in doing something to feel better if they have a negative experience or get in a bad mood, ”said Brown.

The researchers conducted five studies involving nearly 900 people. (47)In the key experiment, the researchers created a sad mood by having subjects listen to music and found that people with low self-esteem were significantly less likely than people with high self-esteem to select a comedy video from among six tapes to break their mood.

“People with lowself-esteem feel resignation because they question whether anything will help and say ‘ I’m not good at breaking or changing a mood, ” Brown said. “They also believe sadness is not something you get rid of and that you learn and grow from sadness. They feel it is not appropriate to try to change a mood. These are not people who would necessarily go to the movies or shopping to feel better. ”

There are things that people with low self-esteem can do to snap a negative mood, according to Brown.

(48) “If you have low self-esteem, you should actively try to rise above the sadness and learn that you will feel better if you do not passively accept sadness. You can get better if you remind yourself to do something. You may have to kick yourself in the butt to go to a movie because it will require a conscious effort rather than something that comes automatically, ” he said.

The other four studies reinforced the idea that low self-esteem people are less motivated to change a negative mood. The initial study asked students to record in a diary a positive or negative experience that happened to them in the next 7 to 10 days and what they did afterwards. (49)The second study found that people with low self-esteem are equally knowledgeable as those with high self-esteem about strategies to repair negative moods.

The final two studies asked people about their experiences when they were in a negative mood. (50) Those with high self-esteem were more likely to express the need to do something to change the mood and less likely to recall instances when they didn’t find a way to improve their mood. Those with low self-esteem, however, were more likely to say such moods are acceptable and that they couldn’t change a mood even if they tried. They also were more likely to say that negative moods sapped their energy.

(49)The second study found that people with low self-esteem are equally knowledgeable as those with high self-esteem about strategies to repair negative moods.