Which type of cell is essential in fighting disease?
erythrocytes
leukocytes
thrombocytes
mast

Hello~ 

I would say the answer is: leukocytes.
Leukocytes are also known as white blood cells, which as you know are essential for disease fighting. 
Erythrocytes are red blood cells.
Thrombocytes are platelets.

Good luck and I hope this helps! If incorrect, please tell me. :)

Nothing will delay it, but drinking some lemon (squeeze 3) would cut it, making it last a few days, but its not good to do that. won't hurt you but the next month will be more cramps.. take some advils with you on the trip