What causes day and night on Earth?

How long does it take the Earth to complete one revolution around the Sun?

What is a leap year?

Which calendar is most widely used in the world today?

Which device measures time very accurately in scientific experiments?

Which of the following is based on the phases of the Moon?

What causes the seasons on Earth?

How many hours are there in a week?

Why do we have time zones on Earth?

Which ancient civilization is known for early calendar development based on stars and planets?