activity level method的用法和样例：
- It shows your activity level during the last 30 days.
- UCM moves changes through the system at the activity level.
- Buford loves Mahinmi's activity level in Game 2 of summer league.
- The strain with the maximum enzyme activity level was a Gram negative bacterium which was identified as Stenotrophomonas maltophilia chitinase strain by 16S rDNA method.
- Consuming less food than other dogs of similar size and activity level.