Given a scientific question, generate a correct answer to it.
--------
Question: What equals the mass of the object (in kilograms) times the acceleration due to gravity (9.8 m/s 2 )?

Answer: weight

Question: What are the two most common vision problems?

Answer: nearsightedness and farsightedness

Question: What are ring-shaped hydrocarbons called?

Answer:
cyclic hydrocarbons