5. Ben's model boat weighs 4 newtons. When he places it in the water it sinks! Explain what happened and what he can do
to make the boat float.

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.

correct answer is a. and d.

the answer is c.

by: nicholas dooley