River water sample, environmental testing, nature background, pollution monitoring
Schlüsselwörter
water,
river,
sample,
testing,
environment,
pollution,
monitoring,
analysis,
science,
nature,
ecology,
research,
quality,
hand,
glove,
laboratory,
clean,
health,
safety,
fluid,
liquid,
transparent,
stream,
creek,
conservation,
protection,
investigation,
assessment,
check,
control,
sustainable,
green,
eco,
earth,
planet,
purity,
study,
experiment,
technology