Q: Which of the following is a crucial piece of evidence supporting scientists' theory of how the continents and the ocean basins formed?

OPTIONS:
- Gravitational forces result in the fusion of small atoms.
- A differentiated iron core expresses magnetic properties.
- Currents redistribute heat in an unevenly heated liquid.
- A stream of charged ions disperses lightweight gases.
A: Currents redistribute heat in an unevenly heated liquid.
Q: Roger poured water over a pile of sand. Some of the sand washed away. This process is similar to which of the following?

OPTIONS:
- The eruption of a volcano
- The erosion of the walls of a canyon
- The uplifting of mountain ranges
- The forming of dunes or mounds in a desert
A: The erosion of the walls of a canyon
Q: What happens at the boiling point of a substance?

OPTIONS:
- liquid becomes a gas
- solid becomes a gas
- liquid becomes a solid
- solid becomes a liquid
A: liquid becomes a gas
Q: The change from day to night on Earth can be explained by

OPTIONS:
- the movement of the Sun.
- the rotation of Earth.
- the movement of the Moon.
- the tilt of Earth.
A:
the rotation of Earth.