Earth's Changing Surface — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. Building a new dirt road on a steep hill most likely causes
A) more soil erosion when it rains
B) fewer earthquakes
C) the rocks below to harden
D) rivers to disappear
Grade 4 NGSS shows that removing vegetation increases erosion during rainstorms.
2. Planting trees along a bare hillside helps protect the land because roots
A) make the soil heavier than water
B) stop earthquakes from happening
C) hold soil in place and slow runoff
D) create more wind erosion
Grade 4 students learn plant roots reduce erosion by anchoring soil and slowing water.
3. A jetty is a long stone wall built into the ocean to
A) speed up beach erosion
B) block wave erosion and protect the beach
C) cause volcanoes
D) make new fossils
Grade 4 NGSS includes jetties as engineered structures that reduce wave erosion.
4. In earthquake zones, engineers design buildings that can
A) float on water
B) sway and bend without breaking
C) stop tectonic plates from moving
D) turn into volcanoes
Grade 4 students learn earthquake-resistant design uses flexibility, not stopping plate motion.
Part B: Fill in the Blank
Write the correct answer on each line.
1. Cutting down forests for farms often increases soil erosion on hillsides.
Grade 4 NGSS connects deforestation to faster erosion of unprotected soil.
2. Sea walls and jetties are structures engineers use to protect coasts from waves.
Grade 4 students learn coastal engineering uses jetties and sea walls against wave erosion.
3. Adding plants whose roots hold soil is one way humans can prevent erosion.
Grade 4 NGSS treats vegetation as a natural solution to reduce surface erosion.
4. Buildings in California are designed to be flexible because of earthquakes.
Grade 4 students link engineering design to local hazards like California earthquakes.
5. Studying past floods and quakes helps engineers prepare for future hazards.
Grade 4 NGSS expects students to see how scientific evidence informs hazard preparation.