The correct answer is "plasma cells".
Plasma cells are differentiated or mature B cells capable of producing antibodies against a particular foreign substance. B cells are stimulated to differentiate into plasma cells when it binds to two receptors of helper T cell; having the T cells "help" the B cells to differentiate to plasma cells. These T cells have the antigenic information passed to them by antigen presenting cells such as dendritic cells and these will be passed to the B cells and plasma cells will produce antibodies against this specific antigen.
There are multiple reasons. 1) there are similar fossils found on different continents. 2) the continents shapes show that they could easily fit together. 3) there are similar rocks, minerals,and land forms on different continents. 4) there's evidence that there was once lush vegetation in areas with extreme cold.
You will some water vapour
Well if you placed the g facing you , it would look upside-down under a microscope , but if you faved it facing the other direction it would look as if it was facing you (the correct way)