<span>In an event of a rattlesnake bite, keeping the person bitten to calm down is the 1st thing to do. When the venom reaches the heart of the victim, it could lead to a fatal death. So by calming down, the circulation of blood is prevented to rise. After which, they directly cut an "x" at the middle of the bite marks and suck out blood as many as possible hoping that the venom is also sucked out too. This was an old technique used in the Oregon trail and may not be the best technique there is nowadays.
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Answer:vitamin Y and vitamin Z are the essential nutrients.
Explanation:
When the researcher treated the mouse cells in the absence of vitamin W and X, the cells survived but when he eventually removed vitamin Y and Z the cells died. This implies that for the cells to grow and survive Vitamin Y and Z which are the essential Vitamin needs to be present. Thanks alot. I hope it helps!