Why are repeated trails required before accepting a hypothesis as true

A 2-year-old tells his mother he is afraid to go to sleep because "the monsters will get him." the nurse should tell his mother to:

Some cancer treatments have a side effect of killing white blood cells. Which best describes a person undergoing this treatment?

An anthropologist discovers the fossilized heart of an extinct animal. The evidence indicates that the organism's heart was large, was well-formed, and had four chambers, with no connection between the right and left sides.

You and your friends have found two different creeks to swim in the first is crystal clear and cold. the second is slightly cloudy, but much warmer. what makes the two creeks different?

The function of chemical substances such as histamine and leukotrienes would be

Look at the word equation below. fatty acids → triglyceride water which describes the chemical reaction taking place? a. hydrolysis of fatty acids b. dehydration of triglycerides c. hydrolysis of triglycerides d. dehydration of fatty acids

Which sentence correctly uses a pronoun in the nominative case as a subject? a. Stefani and me stretch for thirty minutes prior to our vaulting competition. b. Prior to our vaulting competition, Stefani and I stretch for thirty minutes. c.

Why can the same earthquake have different ratings on the Richter Scale and the Moment Magnitude Scale?

Which of the statements best describes the process of crossing over during meiosis? Haploid daughter cells trade chromosomes in pairs. Homologous chromosomes pair up and exchange segments of DNA.

A marine clam is mistakenly added to a freshwater aquarium. What will happen to the clam and why? Popcorn sold at movie theaters is very salty, causing people to become thirsty and to buy so drinks. Explain why salty popcorn causes this thirst.