What you get on paper is so shallow that you never know what you have to do.
Who knows that every grain of Chinese food is hard?
Books are the ladder of human progress.
2. Tell the reasons for the campaign, what to do in the campaign, what to do if you don't choose, show your advantages and make contributions to the class.
In February, the grass grows and the warblers fly, and the willows on the embankment are drunk with spring smoke.
Adhere to the castle peak and not relax, take root and break rocks.
4. gushing; The head is the Tao; Know everything; Before a painter paints, he already has the image of bamboo in his mind-he has a well-thought-out plan/strategy.
5.( 1), negative number: bear, bear, extended to enjoy. Have a long reputation.
(2), scratching: scratching: bending. Metaphor does not yield in the face of pressure, showing great tenacity.
(3), burning: fire. I'm burning with anxiety. Describe very anxious.
(4) Wei: The party was grand.
(5) Head: Head
(6) Doubt: Doubt.
(7), in short.
For our own health, please don't pollute water resources.
Water is the source of life, please don't let the last drop of water in the world become our tears!
7. Guilin's landscape is the best in the world, and Yangshuo's landscape is the best in the world.
Three treasures in Northeast China: Ginseng, Mink and Ursula.
On the second day of the first day of mating, the zygote on the third day turned around.
8. China, USA, Russian Federation, Japan and Australia.
New Year's Day, Tomb-Sweeping Day Arbor Day, Christmas Day in World Environment Day.
9. forget
10. The bookstore has
1 1.( 1)
Generally speaking, the lighting lamps used in family rooms are divided into chandeliers, ceiling lamps, wall lamps, table lamps and floor lamps. Because of the different shapes and performances, they all have their own places in a warm home.
1, chandeliers are suitable for living room lighting. There are many forms of chandeliers, such as cone lights, pointed flat lights, waist lights, five-flowered lights, magnolia lights, olive lights and so on.
2. The ceiling lamp is suitable for the lighting of living room, bedroom, kitchen and bathroom. Commonly used ceiling lamps include square cover ceiling lamp, spherical ceiling lamp, pointed flat round ceiling lamp, hemispherical ceiling lamp, semi-flat spherical ceiling lamp, small rectangular cover ceiling lamp, etc.
3. Wall lamp is suitable for bedroom and bathroom lighting. Commonly used double-headed magnolia wall lamp, double-headed olive wall lamp, double-headed lace wall lamp, jade column wall lamp, mirror wall lamp, etc.
4. Downlight can be installed on the ceiling around the bedroom, living room and bathroom.
5. Long-pole fluorescent lamps (fluorescent lamps) and energy-saving lamps without lampshades should not be used in each room.
6, chandeliers should be equipped with ordinary light bulbs. Ceiling lamps can be equipped with ordinary light bulbs or round and serpentine energy-saving lamps. Wall lamps and desk lamps should be equipped with ordinary light bulbs. Downlights can be equipped with colored bulbs. Ordinary light bulbs should not exceed 40 watts; Colored light bulbs should not exceed 25 watts.
7, the installation height of the chandelier, its lowest point from the ground should not be less than 2.2 meters. The installation height of the wall lamp shall not be lower than 1.8m from the ground. The bottom of the lampshade of floor lamp should be higher than the ground1.8m..
(2)
Legend of lamp
Legend has it that a long time ago, there were many fierce birds and beasts everywhere that hurt people and livestock, so people organized to defeat them. A god bird was trapped and landed on the earth, but was accidentally shot by an unsuspecting hunter. The Emperor of Heaven was very angry when he learned that. He immediately issued a decree, ordering the heavenly soldiers to set fire to the land on the fifteenth day of the first month, burning all the people, livestock and property. The daughter of the Emperor of Heaven is kind-hearted. She couldn't bear to see the innocent suffering of the people, so she risked her life and secretly rushed Xiangyun to the world to tell people the news. When people heard the news, it was like a blow to the head. I'm so scared that I don't know what to do. After a long time, an old man came up with an idea. He said: "On the 14th, 15th and 16th of the first month, every family decorated their houses, set off firecrackers and set off fireworks. In this way, the emperor will think that people have been burned to death. "
Everyone nodded and said yes, and they were ready to go separately. On the night of the fifteenth day of the first month, the emperor looked down and found that for three consecutive nights, the world was red and the noise was deafening. He thought it was the flame of a big fire, and soon. In this way, people saved their lives and property. In order to commemorate this success, every household hangs lanterns and sets off fireworks on the fifteenth day of the first month to commemorate this day.
(3) It is used to illuminate the surgical site, so as to optimally observe small, low-contrast objects with different depths in incision and body control. Because the operator's head, hands and instruments may cause interference shadows at the surgical site, the design of surgical shadowless lamp should eliminate shadows as much as possible and minimize color distortion. In addition, the shadowless lamp must be able to work continuously for a long time without emitting too much heat, because overheating will make the operator uncomfortable and dry the tissue in the operation area.
A surgical shadowless lamp generally consists of a plurality of lamp holders, which are fixed on a cantilever and can move vertically or circularly. The cantilever is usually connected to a fixed connector and can rotate around it. The shadowless lamp adopts sterilization handle or sterilization hoop (curved rail) for flexible positioning, and has the function of automatic braking and stopping to control its positioning, so as to keep proper space above and around the operation site. The fixing device of the shadowless lamp can be placed on the fixed point of the ceiling or wall, or on the track of the ceiling.
For shadowless lamps installed on the ceiling, a transformer of 1 or above should be installed in the remote control box on the ceiling or wall to convert the input power supply voltage into the low voltage required by most bulbs. Most shadowless lamps have dimming controllers, and some products can also adjust the light field range to reduce the light around the operation site (reflections and flashes from sheets, gauze or instruments will make eyes uncomfortable).
(4) From arc lamp to incandescent lamp
Almost at the same time, 1809, the famous British chemist David, who was immersed in electrochemical research, also discovered the arc. He made a big battery himself, used 2000 voltaic cells, and got a stronger and brighter arc.
About 30 years later, someone remembered and applied hard and dense coke instead of ordinary charcoal. Because the burning speed of coke is slower than that of charcoal, the time of arc light is much longer.
Later, French scientists and technicians installed a clock device on the arc device, which enabled it to automatically adjust the distance between two carbon rods. In this way, the first carbon arc lamp was officially born.
1876, Russian electrician Ya Bu Lochekov transformed the arc lamp. He canceled the complicated clock mechanism and the magnetic lamp adjusting device, and let two carbon rods stand side by side, separated by an insulating piece made of clay or gypsum. He also used a device that can constantly change the direction of current, so that two carbon rods alternately act as anode and cathode, so that the combustion speed of the two carbon rods is basically the same, and the distance between the two ends can remain unchanged. Because these two carbon rods stand side by side and glow like candles, people give it a nice name "electric candle".
In the late 1970s, electric candles were all the rage. The electric candles invested and manufactured by the French General Electric Association were once used as street lamps and lit one by one in the street. In Paris alone, thousands of electric candles have replaced the original 70,000 kerosene lamps on the street, making the bustling Paris a veritable city that never sleeps.
From 65438 to 0879, Edison made the first batch of practical carbon filament incandescent lamps in the world on the basis of previous research and practice. Edison used an improved carbonization method to spread a cotton thread with carbon powder, bend it into a horseshoe shape, put it in a clay crucible and heat it at high temperature to make a filament, then sealed it in a glass bulb, and carefully evacuated the air inside. In those two days, 10 and 2 1, this light bulb began to light up and lasted for 45 hours! Edison made a great contribution to the invention of incandescent lamp.
have no time
12. Eclipse is a special astronomical phenomenon, which means that when the moon moves to the shadow part of the earth, the area between the moon and the earth will be blocked by the earth because of sunlight, and the moon will be missing. That is to say, at this time, the sun, the earth and the moon are just (or almost) on the same straight line (the earth is between the sun and the moon), so the light from the sun to the moon will be covered by the earth. As far as the earth is concerned, when an eclipse occurs, the directions of the sun and the moon will be different by 180 degrees, so the eclipse must occur in Wangwang (that is, around the lunar calendar 15). It should be noted that the orbits of the sun and the moon in the sky (called the ecliptic and the ecliptic) are not on the same plane, but have an intersection angle of about 5 degrees, so only when the sun and the moon are located near the intersection of the ecliptic and the ecliptic can they be connected in a straight line to produce an eclipse.
13. Think independently
I am exhausted. ...