Why is an extra day added to the calendar every 4 years? A. Earth's day is actually less than 24 hours long. B. Earth's day is actually more than 24 hours long. C. Earth's year is actually less than 365 days long. D. Earth's year is actually more than 365 days long. Halpp pwease! :>

Melting glaciers is a serious threat to the environment what is the possible consequence of melting glaciers on polar bears?

Identify the type of energy used in each action. the flexing of an arm muscle: a signal transduction process by a neuron: a ball at the top of a hill: 1. electrical energy 2. mechanical energy 3. gravitational potential energy

How does the diagram explain ocean currents? earth tilt 23.5 degreesquestion 1 options: earth's tilt causes uneven heating of earth which causes currents.earth's tilt causes the ocean to move because of gravity.earth's tilt and its rotation cause currents.earth's tilt causes uneven distribution of salt which causes currents.