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Space probe according to the detection of object is divided into lunar probe, probe and interplanetary spacecraft, small body such as a space probe to leave the speed of the earth must be large enough to overcome or get rid of the earth's gravity, realize the deep space flight. The probe orbits the heliocentric elliptical orbit (double-cut orbit) that is tangent to the earth's orbit and the planet's orbit, and may meet the target planet; Increase speed to change the orbit, flew to target the planet can shorten the time in order to ensure the detector fly the double track to the planetary orbits and tangent with the target when the target planets also run to it, must be chosen in the earth and the target planet at a particular moment of relative position detector. Detector can fly around the star, the use of planetary gravitational fields accelerate continuous multiple planets orbit the significant characteristic of space probe is, flying in space for long time, the ground cannot real-time remote control, so must have the ability of autonomous navigation; To fly outside the solar system, away from the sun, solar arrays, and nuclear energy systems; It is necessary to adopt special protective structure to withstand very severe space environment. Landing or walking on the surface of the moon or planet requires some special form of structure
When a child is infected with respiratory tract infection, the pathogenic bacteria can easily enter the middle ear through the eustachian tube and cause otitis media. However, this type of acute otitis media is usually seven to 10 days after a cold, so it is easy to be ignored by parents. After the symptoms of the baby's respiratory infection have gone away, parents need to be concerned about whether the baby has symptoms of otitis media. In addition, the best measure to prevent the childhood suffering from otitis is to actively prevent colds or minimize the cold cycle. When a child is infected with respiratory tract infection, the pathogenic bacteria can easily enter the middle ear through the eustachian tube and cause otitis media. However, this type of acute otitis media is usually seven to 10 days after a cold, so it is easy to be ignored by parents. After the symptoms of the baby's respiratory infection have gone away, parents need to be concerned about whether the baby has symptoms of otitis media. In addition, the best measure to prevent the childhood suffering from otitis is to actively prevent colds or minimize the cold cycle.
For years, car and motorcycle enthusiasts have been replacing their standard steel wheels with larger alloy wheels and hubcaps. At a glance, it's not hard to understand why these alloy wheels are getting to be so popular. Not only do they supply a smoother ride than regular steel wheels, but in addition they are flashier and allow vehicles to face out. This trend will not be lost on manufacturers; even new SUVs, compact cars and vans are coming equipped with large and flashy alloy wheels.
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