Changes in Earth's History Are Recorded

Q13: In a sequence of rock layers we

Q14: Rocks from the Carboniferous period are significant

Q15: In radioactive decay,when the parent material decays

Q16: Conditions for the preservation of fossils are

Q17: Walking along a dry river bed,you find

Q19: The ordering of rocks in sequence by

Q20: The break-up of Pangaea began in the

Q21: The Mesozoic era is known as the

Q22: Life forms in the Precambrian include<br>A)trilobites,brachiopods and

Q23: Going from oldest to youngest,the three periods