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利用如图所示装置探究“物体的动能大小与哪些因素有关”.将小球A、B分别拉到与竖直方向成一定角度θ的位置,然后都由静止释放,当小球摆动到竖直位置时,将与静止在水平面上的木块C 发生碰撞,碰撞后小球静止,木块会在水平面上滑行一定距离后停止.摆长L 都相同,θA<θB,球A、B的质量分别为mA、mB(mA<mB).

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    It's well-known by all the people to greet friends with a smile and a wave.____ However, what happens if your face and body send mixed messages? Would someone tend to believe the look on your face or the way you behave?

    Recently, scientists have dealt with these questions. They found that when a person is staring at your face, he might not believe what he sees if your body doesn't match the feeling that your face shows.____ Previous study had showed that the tone of a person's voice can be more important than the words spoken. For example, most people are more likely not to believe a person who says in a flat voice, “I'm so excited.”

    When talking about emotions conveyed by facial expressions and body language, most scientists suspected that the face was more important. To test if this was true, psychologists from the Netherlands and Boston showed people a number of pictures of isolated faces and isolated bodies that showed anger or fear.____

    An angry face had low eyebrows and tight lips. A frightened face had high eyebrow and a slightly open mouth.____A scared body had arms forward and shoulders square, as if ready to fight back.

These results told the researchers that mixed messages can confuse people. Even when people pay attention to the face, body language surely influences the emotion they read.

    ____And if you want to be understood it helps to avoid sending mixed messages.

A. Studying such mixed messages is nothing new for scientists.

B. So, your body language is important for telling people your feelings.

C. Scientists feel new to study the mixed message that puzzles people.

D. An angry body had arms back and shoulders at an angle, as if ready to fight.

E. Body language can sometimes be misunderstood in different culture backgrounds.

F. They also showed pictures where angry or scared faces were paired with angry or scared bodies.

G. When doing this, your face and body work together to show your friends that you are happy to see them.