题干

按照我国交通管理的规定,“红灯停、绿灯行、黄灯预备”,小刚在科技活动中设计了一个实验电路,用以模拟十字路口的红绿灯,如图所示。请你分析并回答下面的问题。


(1)规定红灯发出的光作为交通的停止信号,其原因是____ 
(2)当单刀多掷开关接通位置“1”时,____ 灯发光,发光的各灯采用的是____ 联方式。
(3)当开关接通位置“3”时,允许____ 方向的车辆通行。

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红光穿透能力强 ,南北绿灯发光、东西红灯发光,并 ,东西

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How to Be Healthy and Happy

    We all want to be healthy, happy, free of stress and more productive in life.

    ⒈Get enough sleep. It not only keeps you healthy but also you will be happier. It is said that “Early to bed, early to rise makes a man healthy, wealthy and wise.”____

    ⒉Drink plenty of water. ____ The benefits of water are amazing. Water helps keep your skin clear, leaving you feeling happier and better about your body. Water is just simply an amazing source in itself for your overall health. Try to drink 8 glasses a day.

    ⒊Smile and laugh. Don't get sad over small problems or take any joke seriously which hurt you. Instead, if you feel so hurt, you prefer to stay away from that friend. ____ Respect your friend from a good perspective. Smile and laugh all the time and you will be happy.

    ⒋____Help your mom do the dishes, help out your dad in the kitchen, clean your room, or do anything that could help your family. It will not only make them love you more, but you will feel happy knowing you have done good even if you moved out twenty years ago and are a father yourself.

    ⒌Have goals. Always believe you can achieve. If you can dream it, you can achieve it, no matter what. ____ Organization plays a very important role in achieving goals, so organize yourself.

A. Help out your family.

B. Don't get in touch with him/her.

C. So make sure you go to sleep earlier.

D. Of course keep goals and dreams realistic.

E. Water is good for everything in your body.

F. The majority of our body is made up of water.

G. However, don't show him that you don't like him.