Researchers call random radio listeners on the phone to rank five different popular songs. This research helps radio stations decide which songs to play more often. This method of gathering data is classified as
a census.
a sample survey.
an experiment.
an observational study.

relative humidity, temperature and dew point -- are bound together in the mathematical relationship below. relative humidity changes when temperatures change. because warm air can hold more water vapor than cool air, relative humidity falls when the temperature rises if no moisture is added to the air. so i would say a

sex cells are usually half's then they find another half and make a fertilize egg

linnaeus is the father of taxonomy, which is the system of classifying and naming organisms. one of his contributions was the development of a hierarchical system of classification of nature. today, this system includes eight taxa: domain, kingdom, phylum, class, order, family, genus, and species.