Projec Apollo, also known as Apollo program, is a series of manned missions to the moon from 196 1 to 1972. The manned moon landing project organized and implemented by the United States in the 1960s and early 1970s is called "Apollo" project, which is an epoch-making achievement in the world space history. The moon landing project started in May of 196 1 year and ended successfully for the sixth time in February of 1972, which lasted about 1 1 year and cost 25.5 billion US dollars. At the peak of the moon landing project, 20,000 enterprises, more than 200 universities and more than 80 scientific research institutions participated, with a total number of more than 300,000 people. The Apollo program was a great success, but there were several serious crises in the program, including the fire that killed Virgil Grissom, edward white and roger chaffee during the Apollo/KLOC-0 test. The explosion of the oxygen tank of Apollo 13 and the toxic gas released when the Apollo-Soyuz test plan returned to the atmosphere almost killed the astronauts on the mission.

Concrete, referred to as "concrete (tóng)", refers to the general name of engineering composite materials in which aggregates are bonded into a whole by cementing materials. Generally speaking, the term concrete refers to cement as cementing material and sandstone as aggregate; Cement concrete, also known as ordinary concrete, is made by mixing and stirring water (including admixture and admixture) in a certain proportion, which is widely used in civil engineering.

Life-creating IVF is a baby developed by artificially fertilizing eggs and sperm in vitro, developing into early embryos, and then transplanting them into the mother's uterus. "IVF" appeared with the development of in vitro fertilization technology, which was originally developed by British obstetrician Patrick? Steptoe and physiologist Robert? Edwards successfully participated in this research.

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