*Question*
Q: For a star to form, what force pulls gas and dust into the center of the nebula? Choices: - weight - centrifugal force - motion - gravity A:
**Answer**
gravity

*Question*
Q: What do vertebrate chordates possess that invertebrate chordates do not? Choices: - parasite - Thumb - Milk production - backbone A:
**Answer**
backbone

*Question*
Q: What type of salts are secreted into the small intestine to aid in the digestion of fats? Choices: - zinc - Table Salt - sodium - bile A:
**Answer**
bile

*Question*
Q: Ionic bonds are electrostatic attractions between two oppositely charged what? Choices: - molecules - gasses - compounds - ions A:
**Answer**
ions