The idiom 'Burn the midnight oil' means 'To work late into the night'. This idiom originates from the days before electric lighting, when people used oil lamps for light, especially when they stayed up late at night to read, write, or study. The phrase figuratively refers to working very late hours, often past midnight, to accomplish a task.
Understanding idioms involves recognizing that their meanings cannot typically be deduced from the literal meanings of their individual words. In the case of this idiom:
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