The idiom "bite the bullet" means to force oneself to do something unpleasant or to endure a painful situation with courage and determination. Let's review each option to find the correct usage:
The correct usage is: He bit the bullet and finally accepted the unpleasant assignment.
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