An idiom is a group of words established by usage as having a meaning not deducible from those of the individual words. The idiom "Bite the bullet" means to face a difficult situation bravely. This expression originates from the historical practice of having patients bite on a bullet during surgical procedures as a way of coping with the pain when anesthesia was not available.
Breakdown of Options:
Thus, the correct interpretation of "Bite the bullet" is to bravely confront a challenging situation.
Rearrange the following parts to form a meaningful and grammatically correct sentence:
P. a healthy diet and regular exercise
Q. are important habits
R. that help maintain good physical and mental health
S. especially in today's busy world