Which reason BEST supports this opinion: There is a good chance of life on other planets.I really want to meet people from other worlds someday.Our galaxy contains many planets that are similar to Earth.In a movie about aliens, the aliens turned out to be insects.Only a dumb person would think that only Earth has life.

To determine which reason best supports the opinion that there is a good chance of life on other planets, let's analyze each option step by step:

1. "I really want to meet people from other worlds someday."

   • This statement expresses a personal desire or hope but does not provide any scientific or logical reasoning to support the opinion. It is based on personal feelings rather than evidence.

2. "Our galaxy contains many planets that are similar to Earth."

   • This statement provides a factual basis for the opinion. It suggests that because there are many Earth-like planets in our galaxy, the conditions necessary for life might exist elsewhere, increasing the likelihood of life on other planets.

3. "In a movie about aliens, the aliens turned out to be insects."

   • This statement refers to a fictional scenario from a movie. While it might be interesting, it does not provide any real evidence or scientific reasoning to support the opinion about the existence of life on other planets.

4. "Only a dumb person would think that only Earth has life."

   • This statement is an ad hominem attack and does not provide any evidence or reasoning. It dismisses opposing views without offering a logical argument or supporting evidence.

Based on the analysis, the reason that BEST supports the opinion "There is a good chance of life on other planets" is:

"Our galaxy contains many planets that are similar to Earth."

This reason is grounded in scientific observation and provides a logical basis for the opinion.