3.29 Main Idea and Details Worksheet

Volcanoes can seem only destructive, but they can also help farming over time. When volcanic ash and lava break down, they add minerals such as potassium and phosphorus to the soil. These minerals can make soil rich for crops. That is why some people farm near volcanoes even though eruptions are dangerous. Farmers watch warning systems and have evacuation plans in case the volcano becomes active. Living near a volcano involves risk, but the long-term soil benefits can be valuable.

On the International Space Station, astronauts cannot easily bring huge amounts of water from Earth. Instead, they recycle. Water from humidity in the air is collected as it condenses, similar to how water forms on a cold glass. Wastewater is cleaned through filters and special treatments. After being purified, the water can be used again for drinking and washing. Recycling water reduces the number of supply missions needed and helps astronauts live in space for long periods.

When a city plans transportation, it must think about how people move in different ways. Adding bike lanes can make cycling safer and may encourage some people to ride instead of drive. However, a new bike lane might reduce space for car traffic or parking on a busy street. City planners study traffic counts, crash reports, and community opinions before making changes. Sometimes they test a new lane with temporary paint and cones before building it permanently. Good planning tries to balance safety, access, and travel time for everyone.