Answer: B. They are a first line of defense that can begin killing pathogens immediately.
Explanation:
B-lymphocytes are not the first line of defense. On the contrary, innate immune cells such as basophils, dendritic cells, eosinophils, Langerhans cells, mast cells are the body's first line of defence.
1s orbital
Explanation:
The electron has to go into the first energy level, in the 1s orbital. Helium, with two protons, will have two electrons. These are placed one at a time into the 1s orbital. This makes helium a very contented atom.
Option A is true about blood pH.
Food Webs <span>show how plants and animals are connected in many ways to help them all survive. </span>Food Chains just<span> follow just one path of energy as animals find food.
So the answer is: Scientists prefer the usage of food webs over food chains due to the fact that food webs are more elaborate and more detailed than the food chain.</span>
