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
Reorder the sentences into a meaningful paragraph:
1. The sun was setting behind the hills.
2. Birds were returning to their nests.
3. The sky was painted in shades of orange.
4. A cool breeze started blowing.
Rearrange the following parts to form a meaningful and grammatically correct sentence:
P. that maintaining a positive attitude
Q. even in difficult situations
R. is essential for success
S. and helps overcome obstacles effectively
For any natural number $k$, let $a_k = 3^k$. The smallest natural number $m$ for which \[ (a_1)^1 \times (a_2)^2 \times \dots \times (a_{20})^{20} \;<\; a_{21} \times a_{22} \times \dots \times a_{20+m} \] is: