Answer:
answer is; someone did it
The letter "E"
because it happens once a minute (there's 1 E in a minutE)
twice in a wEEk (there is 2 E's in week)
and once in a yEar (there's 1 E in year)
You could develop a study plan that works with your daily routine so that your brain knows that it’s time to pay attention.
The figurative language used here would be a metaphor.