Which of Saturn's moons was discovered first?
If a moon is 107.6 km in diameter, how many cm would this be if the scale is 1 km = 2cm
The spinal cord, a bundle of nerves inside the spine, is part of what body system?
This organ belongs to the ______ system.
칼슘의 원소 기호는?
Ag의 원소 이름은?