Fact 1: Most canyons are formed by flowing rivers through erosion over long periods of time. Fact 2: Deep canyons and valleys are carved out. Given the two facts above, answer the question "What are formed by flowing rivers through erosion over long periods of time?" with the following options: - deserts - a hydraulic system - deep valleys - pyramids - Calcium carbonate - patch reefs - buildings - Sediment
deep valleys

Fact 1: Echinoderms have a unique water vascular system with tube feet. Fact 2: Echinoderms are represented by the starfish. Given the two facts above, answer the question "What kind of animals has a water vascular system with tubed feet?" with the following options: - animals - starfish - reeds - insects - warm-blooded - sponges - sea coral - four limbs
starfish

Q: Fact 1: Roundworms reproduce sexually. Fact 2: Sexual reproduction is the combination of egg and sperm to form larvae. Given the two facts above, answer the question "Roundworms reproduce by combining an egg and sperm to form what?" with the following options: - larvae - plants - offspring - Flowers - seeds - infants - kittens - puppies
A: larvae

Question: Fact 1: Migration is a type of movement that changes population size. Fact 2: Insects can also migrate. Given the two facts above, answer the question "what can change population size through movement?" with the following options: - cows - ducks - goats - animals - relocation - mammals - fur seals - insects
Answer: insects

*Question*
Fact 1: Courtship is behavior that is intended to attract a mate. Fact 2: Moose courtship begins in autumn. Given the two facts above, answer the question "When do moose begin behavior intended to attract a mate?" with the following options: - Winter - howling - The past - sweating - Summer - autumn - ligt - movement
**Answer**
autumn

Q: Fact 1: Radioactive dating is used to determine the age of fossils. Fact 2: Radioactive dating requires the use of a decay curve. Given the two facts above, answer the question "What is used to determine the age of fossils?" with the following options: - Calcium carbonate - dinosaurs - a barometer - electron microscope - a thermometer - a decay curve - chemical equations - Physical weathering
A: a decay curve