Which best describes Mercury's plains?
a. heavily impacted with craters and large rays
b. solidified lava flows that are a uniform gray color
c. a geologically active surface of molten lava
d. solidified lava flows rich in dark basalts
e. a rich layer of soil containing iron and silicate
Question 2
A planetary nebula is a(n) ____.
a. expanding envelope of ionized gas expelled by a dying medium-mass star
b. expanding envelope of neutral gas and dust expelled by a dying medium-mass star
c. contracting envelope of dusty material from planets destroyed by a dying medium-mass star
d. contracting envelope of ionized interstellar medium absorbed by a dying medium-mass star
e. expanding atmosphere of a medium-mass star as it becomes a red giant
The rotifer, Brachionus calyciflorus, is a large predator that consumes the smaller algae, Chlorella
Mutualisms, such as those that occur among plants and pollinators, generally involve large numbers o
Portrait of a Shy Albatross. Note the large, hooked beak and nasal tubes.
The Interiors of Earth and Mercury
The Taung Child, the first of the australopithecines to be discovered, is the type specimen for Aust