Lubricants, Magnetic Levitation, Ball Bearing
Answer:
The biologist is studying about the ecological community.
Explanation:
The ecological community refers to the community in which population of different types of species survives together. As the biologist is observing about the interaction of different populations of Pennsylvania region, it can be inferred that the he is studying about the ecological community of Pennsylvania region.
The population surving in the community interact with each other through different modes of interaction. It may either parasitic, or mutual, or competitive or predication or commercialism.
Answer:
The average adult, when resting, inhales and exhales about 7 or 8 liters of air per minute. That totals about 11,000 liters of air per day. Inhaled air is about 20-percent oxygen. Exhaled air is about 15-percent oxygen.
Explanation:
The correct option is D. all of the above
Answer:
B- Hemoglobin E O is the answer