I think it’s D. H2, NaCI, CO
Barking when frightened
Explanation
The others require you to teach the dog how to do it but I dog doesn’t need teaching to bark it comes naturally
Explanation:
Water provides a safety net for mosquitoes to move into developmental periods and grow. In the egg stage, the female lays roughly 300 eggs that float atop the water's surface. This is why it is so important to eliminate any standing water around your property.
Ok, think about it. Does your skin prevent germs from getting inside you?
Does your skin prevent water from leaving the body too quickly? Does your skin protect your insides from getting damaged when you fall? Do you put food on your skin to absorb nutrients, or do you put food in your mouth like a normal person?
Answer:
The right atrium takes blood from the veins and pumps it into a ventricle
Please mark as brainliest
