Answer:
How invisible particles can be observed in outer space. ... We call this invisible mass dark matter since it cannot reflect light. Gravitational effects are only way we can detect its presence.
Answer:
Due to lack of technology.
Explanation:
It took several centuries before the civilizations of the two hemispheres had communication because of lack of technologies that can make a bridge of communication between two hemisphere. People are not interested in research and having old wrong beliefs that prevent them from growth and development but due to renaissance movement people get rid of false and wrong beliefs and work for the advancement of technology which leads to communication between two hemisphere.
The problem is that "Cupid" is now lost (thought to have been destroyed in 1698 in a fire on London), so we only know about the characteristics of Cupid from stories. It is said to have been treated with acidic earth with Michaelangelo at the time, to make it appear older. The cupid was sleeping on a bed-like structure.
Your answer is b hope it’s right
