What kind of gas cloud is most likely to give birth to stars?
A) a hot, dense gas cloud
B) a cold, dense gas cloud
C) a cold, low-density gas cloud
D) a hot, low-density gas cloud
Question 2
According to our theory of solar system formation, why does the Sun rotate slowly today?
A) The Sun once rotated much faster, but it transferred angular momentum to charged particles caught in its magnetic field and then blew the particles away with its strong solar wind.
B) The Sun once rotated much faster, but it transferred angular momentum to planets and other objects during close encounters.
C) The Sun once rotated much faster, but it lost angular momentum due to internal friction.
D) The Sun once rotated much faster, but it lost angular momentum because everything slows down with time.
E) The Sun was born rotating slowly because the solar nebula had very little angular momentum.
Plotting the Ages of Stars
Stellar Birth Rates
Baseline Pulse, Respiration, and Blood Pressure Values from Birth to Adolescence
Country of Birth of Authorized U.S. Immigrants
Birth Control Methods and Abortion
Relationship between birth weight and mortality in humans