Why do scientists think that our solar system must have formed sometime after nearby supernovae explosions?
A) existence of heavy elements
B) solar temperature too low
C) our Sun is a G-type star
D) They don'tscientists believe our Sun is among the first generation of stars.
Question 2
You discover a binary star system in which one member is a15MSun main-sequence star and the other star is a 10MSun giant. How do we believe that a star system such as this might have come to exist?
A) The giant must once have been the more massive star but transferred some of its mass to its companion.
B) Despite the low odds of finding a system with two such massive stars, there is nothing surprising about the fact that such systems exist.
C) The two stars probably were once separate but became a binary when a close encounter allowed their mutual gravity to pull them together.
D) The main-sequence star probably is a pulsating variable star and therefore appears to be less massive than it really is.
E) Although both stars probably formed from the same clump of gas, the more massive one must have had its birth slowed so that it became a main-sequence star millions of years later than its less massive companion.
The mammalian urinary system including the basic functional unit of the nephron.
The protonephridial filtration system of flatworms.
nervous system
The Rodent Accessory Olfactory System
Block Diagram of a High Concentrate Nitric Acid System for Dual-Stage Pressure Production of Nitric
Soil as a system