When a stalagmite has an oxygen-18 to ____________________ ratio ...

[arivle123]

When a stalagmite has an oxygen-18 to ___________________ _ ratio that is low, the climate at the
  time the stalagmite formed was relatively ___________________ _ Fill in the blank(s) with the appropriate word(s).

Question 2

Prior to the discovery of radioactivity in the late ___________________ _ century, geologists were
  able to develop a(n) ___________________ _ geologic time scale. Fill in the blank(s) with the appropriate word(s).

[ciecieme]

Answer to Question 1

oxygen 16; cool

Answer to Question 2

nineteenth, relative