Author Question: The most striking and largest valley in the solar system is A) the Grand Canyon in Arizona. B) ... (Read 23 times)

cabate · **on:** Jul 27, 2018

The most striking and largest valley in the solar system is

A) the Grand Canyon in Arizona.
B) Gwenivere on Venus.
C) the Discovery Scarp of Mercury.
D) Valles Marineris on Mars.
E) Valhalla on Callisto.

Question 2

The critical temperature to initiate the proton-proton cycle in the cores of stars is:

A) 3,000 K.
B) 5,800 K.
C) 2,300,000 K.
D) 10 million K.
E) 100 million K.