The impact of meteorites produce most of the earthquakes. If you have problems with this question, check Chapter VI.8C in the Review 10. Iridium is poisonous for dinosaurs. Iridium is much more abundant in meteorites than in the Earth's crust. Iridium is created in the melting of the Earth's crust during a meteorite impact.
Iridium is dug out of the Earth's interior during a meteorite impact.
If you have problems with this question, check Chapter VI.8C in the Review 11. If you have problems with this question, check Chapter VIII.2A in the Review 12. The Enterprise arrives at a star system with a blue star. The crew finds that the star has approximately the same size as the sun. It is less luminous than the sun.