Science worksheet illustrating the relationship between Earth's axial tilt and the changing seasons.

Problem Analysis:

The task involves understanding how the Earth's tilt causes seasons. The worksheet provides a diagram of the Earth's orbit around the Sun, showing different positions of the Earth throughout the year. The task requires:

1. Drawing lines of direct sunlight.
2. Labeling which picture shows summer and which shows winter.
3. Filling in blanks about the Earth's position relative to the Sun during specific seasons.

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Solution:

#### Step 1: Draw the lines of direct sunlight
- Direct sunlight refers to the path of sunlight that hits the Earth most directly (perpendicularly). This occurs when the Sun is directly overhead at the equator or other latitudes depending on the time of year.
- In the diagram:
- At the summer solstice, the Northern Hemisphere is tilted toward the Sun, so the direct sunlight hits the Northern Hemisphere more directly.
- At the winter solstice, the Northern Hemisphere is tilted away from the Sun, so the direct sunlight hits the Southern Hemisphere more directly.
- At the spring and autumn equinoxes, the Earth is neither tilted toward nor away from the Sun, so the direct sunlight hits the equator most directly.

#### Step 2: Label which picture shows summer and which shows winter
- Summer: Occurs when the Northern Hemisphere is tilted toward the Sun. In the diagram, this is the position where the Northern Hemisphere is leaning toward the Sun.
- Winter: Occurs when the Northern Hemisphere is tilted away from the Sun. In the diagram, this is the position where the Northern Hemisphere is leaning away from the Sun.

#### Step 3: Fill in the blanks
- When the Earth is leaning toward the sun, it is _________.
- When the Earth is tilted toward the Sun, the hemisphere facing the Sun experiences summer because it receives more direct sunlight and longer daylight hours.
- When the Earth is leaning away from the sun, it is _________.
- When the Earth is tilted away from the Sun, the hemisphere facing away from the Sun experiences winter because it receives less direct sunlight and shorter daylight hours.

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Final Answers:

1. Lines of direct sunlight: Draw lines perpendicular to the Earth's surface where the sunlight hits most directly. For example:
- At the summer solstice, draw a line perpendicular to the Northern Hemisphere.
- At the winter solstice, draw a line perpendicular to the Southern Hemisphere.
- At the equinoxes, draw a line perpendicular to the equator.

2. Labeling summer and winter:
- The picture where the Northern Hemisphere is tilted toward the Sun shows summer.
- The picture where the Northern Hemisphere is tilted away from the Sun shows winter.

3. Fill in the blanks:
- When the Earth is leaning toward the sun, it is summer.
- When the Earth is leaning away from the sun, it is winter.

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Final Answer:

\[
\boxed{\text{summer, winter}}
\]