Earth's atmosphere became oxygen rich about 2.45 ________ years ...

[audragclark]

Earth's atmosphere became oxygen rich about 2.45 ________ years ago.
 
  A) billion
  B) million
  C) trillion
  D) thousand

Question 2

All true oceanic islands are ________ in origin.
 
  A) collisional
  B) erosional
  C) metamorphic
  D) sedimentary
  E) volcanic

[jasonq]

Answer to Question 1

A

Answer to Question 2

E

[audragclark]

Excellent

[pratush dev]

Thanks for the timely response, appreciate it