| List I | List II | ||
| A | Pleurobrachia | I | Mollusca |
| B | Radula | II | Ctenophora |
| C | Stomochord | III | Osteichthyes |
| D | Air bladder | IV | Hemichordata |
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