Author Question: Since life arose on Earth, ________ major extinctions have occurred. A) one B) two C) four D) six ... (Read 97 times)

xclash · **on:** Jul 14, 2018

Since life arose on Earth, ________ major extinctions have occurred.

A) one B) two C) four D) six E) eight

Question 2

Which of the following is true of the chemical composition of seawater?

A) The highest salinity values of seawater are found near landmasses and at higher latitudes.
B) The chemical properties of seawater show very little latitudinal variability, though some minor variability with depth.
C) Eighteen elements account for 75 of the dissolved matter in seawater.
D) Samples of ancient seawater suggest a great deal of chemical variation over the Earth's history.
E) Seawater contains dissolved gases, suspended and dissolved organic matter, and many trace elements.