B: brown
B:black
brown dog: bb
First black dog: BB
Second black dog: Bb
Black is dominant
Simple. Air has mass. And if air has mass it also has weight. You can feel air when the wind blows. Or do an experiment. Weigh an empty container. Then pump it to a vacuum. Weigh it again. The difference is the weight of the air inside.
By eating plants and other animals, because they obtain their carbon from food.
The answer is A:it does not have a plasma membrane. if you need proof https://www.bing.com/search?q=does%20a%20virus%20have%20a%20plasma%20membrane&qs=n&form=QBRE&sp=-1&p... i did a simple search