Q: What is the main source of energy for the water cycle?

OPTIONS:
- electricity
- erosion
- gravity
- sunlight
A: sunlight
Q: Crows are found throughout many parts of the world. They are black birds with excellent hearing. In the wild they live for six to seven years. Some crows in Japan open hard-shelled nuts by dropping them in front of moving cars. Which of these is a learned behavior?

OPTIONS:
- Having excellent hearing
- Living six to seven years
- Dropping nuts in front of cars
- Having black feathers
A: Dropping nuts in front of cars
Q: What is determined by the speed that Earth rotates on its axis?

OPTIONS:
- the length of a day
- the energy that reaches a location
- the temperature of water in the ocean
- the number of seasons in a year
A: the length of a day
Q: Feathers, wings, and the hollow bones of birds are examples of

OPTIONS:
- adaptations for flight
- responses to stimuli
- unnecessary body parts
- reproductive structures
A:
adaptations for flight