Bacteria usually have very short life spans. However, in 1989, the skeleton of a well preserved, 11,000-year-old Mastedon was found in Ohio. Scientists found an intestinal bacterium in its rib cage that believe was its last meal. The bacterium was not found in the surrounding peat. Therefore, the bacterium must be over 11,000 years old.

问答题Bacteria usually have very short life spans. However, in 1989, the skeleton of a well preserved, 11,000-year-old Mastedon was found in Ohio. Scientists found an intestinal bacterium in its rib cage that believe was its last meal. The bacterium was not found in the surrounding peat. Therefore, the bacterium must be over 11,000 years old.

问答题误吸的危险因素包括什么