An organized procedure to study something under controlled conditions.

compost can be added to topsoil as a:

pesticide

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.

your body is trying to warm itself up. or more precisely, sensors in your skin send messages to your brain to generate heat to your body.