According to Hess’s theory, what might happen if the magma under a mid-ocean ridge cools? The magnetic stripes might reverse direction.
The deep-ocean trench might become deeper.
The crust at the ridge might form more quickly.
The plates on either side of the ridge might stop moving.

Liquid from a brewery fermentation contains 10% ethanol and 90% water. part of the fermentation product (50,000 kg/h) is pumped to a distillation column on the factory site. under current operating conditions, a distillate of 45% ethanol and 55% water is produced from the top of the column at a rate of one-tenth that of the feed. what is the composition of the waste "bottoms" from the still?