tester or sampler
A person who believes in aliens is often referred to as an "alien enthusiast" or someone who is "believes in extraterrestrial life."
A self-centered person or egocentric individual is someone who thinks the world revolves around them.
A physicist and a pathologist. There is no single term for someone that does both. A pathologist may specifically study the effects of gravity on vaccines
An astronaut is a person who is trained to travel and explore in space. The first astronauts to land on the moon landed on July 21, 1969 in the Apollo 11
Referring to someone's mother as an astronaut is typically used as an insult because it suggests that the person's mother is absent or neglectful, since astronauts are often away from their families for extended periods of time due to their job responsibilities. It implies that the person has a strained or distant relationship with their mother, which can be hurtful.
The person is a blackmailer.
can you call someone a welth of knowledge
a person
A person?
A person who is tested on is typically referred to as a "test subject" or "participant" in a research or experimental setting.
You call that person a scholar.
an ally
You would call them someone who peruses.
You can call someone who does not lie honest, truthful, trustworthy, or sincere.
someone who works for a business
You can call someone who is wise and has good sense as a sage or a wise person.
If someone tries to make you feel jealous.You must call that person a despo or a looser and a jerky person.