Stromatolite fossils are the oldest known fossils<span>, that formed 3.5 billion years ago when the environments of Earth were too hostile to support life as we know it today. They </span><span>are layered mounds, columns, and sheet-like sedimentary rocks</span><span>
Stromatolite fossils indicate that </span>life must have arisen quite a bit earlier, perhaps 3.9 billion years ago.
The whooping cough vaccine is harmless
for the patient and the baby. Doctors and midwives who major in in caring for
pregnant women approve that it is significant to be acquired throughout the
third trimester of pregnancy. Adults who are 19 years old and older must only acquire
one dosage of the Tdap vaccine.
