1. The planets are kept in motion in their respective orbits by Gravitation and centrifugal force.
2. Lunar eclipse does not occur every month because the moon’s orbit is not all the time in the same plane as the earths.
3. Lunar eclipse is caused when the earth comes between the sun and the moon.
4. First Canadian to walk in space was Chirs Hadifield.
5. First Cuban in space Arnaldo Tamayo Mendez.

Click for complete file of 300 MCQs