*Question*
Q: What helps represent age-sex structure of the population? Choices: - habitat chart - density graph - biome model - population pyramid A:
**Answer**
population pyramid

*Question*
Q: What builds up in an artery and reduces blood flow? Choices: - pressure - calcium deposits - surface tension - plaque A:
**Answer**
plaque

*Question*
Q: Potential energy is present in objects that are what? Choices: - crystals - rigid - unstable - elastic A:
**Answer**
elastic

*Question*
Q: What 3 types of friction occur between solid surfaces? Choices: - static , arching , rolling - static,desending,sliding - static , ascending , rolling - static, sliding, rolling A:
**Answer**
static, sliding, rolling