Q: Which of the following is a cause of the ocean levels periodically rising and then falling? OPTIONS:
- the slight tilt of the Moon
- the force of gravity from the Moon
- the convection within Earth's mantle
- the revolution of Earth around the Sun
A: the force of gravity from the Moon

Which statement correctly describes a relationship between two human body systems?
OPTIONS:
- The digestive system absorbs nutrients which are transported by the nervous system.
- The digestive system absorbs nutrients which are transported by the circulatory system.
- The circulatory system exchanges gases which are transported by the nervous system.
- The circulatory system exchanges gases which are transported by the digestive system.

The digestive system absorbs nutrients which are transported by the circulatory system.

Q: Which of the following is found farthest from the center of an atom? ---- OPTIONS:
- nucleus
- proton
- neutron
- electron

A: electron

In a desert environment, cactus wrens often build their nests in cholla cacti to avoid predators. This behavior does not hurt the cacti. Which type of relationship do cactus wrens and cholla cacti demonstrate?
===
OPTIONS:
- competitive
- commensalism
- mutualism
- parasitism

commensalism

Question:
Which statement correctly describes a relationship between the distance from Earth and a characteristic of a star?
OPTIONS:
- As the distance from Earth to the star decreases, its size increases.
- As the distance from Earth to the star increases, its size decreases.
- As the distance from Earth to the star decreases, its apparent brightness increases.
- As the distance from Earth to the star increases, its apparent brightness increases.
Answer:
As the distance from Earth to the star decreases, its apparent brightness increases.

Question:
Weather forecasts are more accurate today than in the past due to
OPTIONS:
- global warming
- air-quality control
- plate tectonics
- use of images from space
Answer:
use of images from space