It can allow the molecule (like water) to be polar because it has a negative and positive side to it (oxygen holds the negatives tight causing the hydrogens to be positive).
I would say that it would be excessive rain and heat. Because, after a drought and a flood happen, standing water is home to mosquitos which carry malaria. I hope this helps!
A) At 0 C water forms ice but as mentioned above F) water's greatest density occurs at 4 C and it decreases below 4 C so ice is lighter than 4C water, thus, at 0C ice comes to surface and acts as insulator thereby preventing lower water from freezing.
