There are a host of engineering problems that must be faced in order to safely transit astronauts to and from the moon. Key challenges include:
1. Takeoff
Generating enough force to escape Earth's gravity requires enormous energy.
2. Propulsion
Ensuring enough fuel is available to return to Earth.
3. Artificial Environment
Creating an artificial life support system for the occupants of the ship. This must supply oxygen, filter out surplus carbon dioxide, provide heating, radiation shielding and a perfect seal to protect the occupants from the cold vacuum of space.
4. Food and water
Ensuring enough supplies are packed to keep all the occupants alive during the multi-day trip.
The answer is C. I hope this helps
Why do people answer bs, its capitalism i believe
Porcelain & tea innovation of the Song Dynasty(AD 960-1280) has the greatest impact on the expansion of global empires.It was really in the Song Dynasty that tea reached its cult status. It was drunk out of very beautiful, extraordinarily exquisite tea bowls made from porcelain, one of the glories of the Song Dynasty.The word "china" is appropriate for porcelain, because the Chinese developed the technology for its production. The Song Dynasty ceramic industry was basically the first commercialized industry.They produced the pieces in mass quantities for the imperial palace, but also for this newly arisen class of scholar-officials and an urban elite and for these restaurants.
