One

Two

Three

Four

Foxes → beetles → grasses → songbirds

Grasses → beetles → songbirds → foxes

Foxes → songbirds → beetles → grasses

Grasses → foxes → songbirds → beetles

Water vapor melted on the student's eyeglasses.

Water vapor evaporated off the student's eyeglasses.

Water vapor condensed on the student's eyeglasses.

Water vapor froze on the student’s eyeglasses.

7 days

15 days

22 days

30 days

Refraction

Absorption

Reflection

Transmission

Limited access to sunlight

Limited access to water

Limited access to nutrients

Limited access to oxygen

The weather became cooler and rainy.

The weather became cooler and clear.

The weather became warmer and rainy.

The weather became warmer and clear.

A cold front moves cool, dry air from north to south.

A cold front moves warm, dry air from north to south.

A cold front moves cool, moist air from south to north.

A cold front moves warm, moist air from south to north.

1.Use a magnet to remove the particles that are magnetic. 2.Pour the remaining mixture through filter paper.

1.Pour the new mixture through filter paper. 2.Use a magnet to remove the particles that are magnetic.

1.Boil the mixture. 2.Pour the new dry mixture through filter paper.

1.Pour the mixture through filter paper. 2.Boil the water that passes through the filter paper.

Gravity caused the car to speed up when rolling down the ramp and slow down when rolling across the floor.

Friction caused the car to speed up when rolling down the ramp and slow down when rolling across the floor.

Gravity caused the car to speed up when rolling down the ramp, and friction caused the car to slow down when rolling across the f loor.

Friction caused the car to speed up when rolling down the ramp, and gravity caused the car to slow down when rolling across the f loor.