*Question*
Q: When both momentum and kinetic energy are conserved in a closed system, the collision is called what? Choices: - a static collision - a spontaneous collision - an accidental collision - an elastic collision A:
**Answer**
an elastic collision

*Question*
Q: The entry of acidic chyme into the duodenum stimulates the release of what? Choices: - progesterone - gastrin - oxygen - secretin A:
**Answer**
secretin

*Question*
Q: What describes how close an estimate is to a known standard? Choices: - diversity - frequency - precision - accuracy A:
**Answer**
accuracy

*Question*
Q: What do hydrophilic substances have an affinity for? Choices: - air - soil - heat - water A:
**Answer**
water