*Question*
Q: Rain, snow, sleet, and hail are all examples of what? Choices: - temperature - erosion - liquids - precipitation A:
**Answer**
precipitation

*Question*
Q: What is the closed circulatory system of humans and other vertebrates called? Choices: - digestive system - reproductive system - respiratory system - cardiovascular system A:
**Answer**
cardiovascular system

*Question*
Q: What is the term for a particle outside the nucleus of an atom that has a negative electric charge? Choices: - proton - ion - neutron - electron A:
**Answer**
electron

*Question*
Q: What is the general name for a wave that travels along the surface of a medium? Choices: - stack wave - speed wave - light wave - surface wave A:
**Answer**
surface wave