Multiple choice cloze #2

Origin of the planets

The planets are ................. of material quite different from the Sun.
The Sun is ................. entirely composed of hydrogen, and some helium.
Its energy comes from the ................. of hydrogen to helium.
In ................., the "terrestrial" planets are composed almost entirely of larger atoms and molecules which cannot have come from the Sun
It follows, therefore, that the ................. which forms those planets must have come from another source or sources.
................. sources were the atoms formed in supernovae explosions by much larger and much shorter-lived stars in the Sun's neighbourhood as it moved in the galaxy
This material was ................. by the Sun's gravity and pulled along to become the basic material out of which the planets condensed.
The same considerations ................. to other planetary systems in the galaxy.