Short-term studies relate shortterm (often day-to-day) changes in PM concentrations and changes in daily mortality rates up to several days after a period of elevated PM concentrations.
PM concentrations can change from one day to the next.
PM concentrations are very stable and only change over decades of time.
The man is brushing his teeth.
Trucks pass workers on sidewalk
Two grownups escort a group of young kids.
Hong Kong never returned.
I felt much better last night.
The festivals are very special, and it is recommended that you try to fit them into your trip.