Answer:
The basic steps of the scientific method are: 1) make an observation that describes a problem, 2) create a hypothesis, 3) test the hypothesis, and 4) draw conclusions and refine the hypothesis.
Explanation:
They have longer periods of revolution.
Answer:
Moist walls - gases dissolve in the moisture helping them to pass across the gas exchange surface. Permeable walls - allow gases to pass through. Extensive blood supply - ensuring oxygen rich blood is taken away from the lungs and carbon dioxide rich blood is taken to the lungs.
Answer:Ways of protecting one's self from human sources of biological hazards include: Effective use of personal protective equipment such as hand gloves, nose masks, face cover, shoe cover.
Explanation:Human sources of biological hazards may include waste products from human such as faeces, urine and also fluids such as blood from bleeding wound, saliva and so on. These substances may harbor bacterial and viral infections which may result in biological hazards. Therefore, good personal hygiene and use of personal protective equipment will protect one from biological hazards related to human sources.