The plants or shrubs have not been trimmed and are overgrown .
It is certain that the plants at the park are overgrown because the groundskeeper has died .
It is impossible that the plants at the park are overgrown because the groundskeeper has died .
It is certain that the plants at the park are overgrown because the groundskeeper has died .
The plants at the park are overgrown because the groundskeeper has died .