Question

the passage below describes an experiment. brennan and his neighbors wanted to attract more woodpeckers to their yards. they read that woodpeckers often eat sunflower seeds. the neighbors wanted to find out if filling their bird feeders with sunflower seeds would increase the number of woodpeckers that visited their yards. so, four of the neighbors filled their feeders with sunflower seeds. another four neighbors left their feeders empty. every morning for a month, the neighbors counted the number of woodpeckers they saw in their yards. in this experiment, which were part of a control group? the yards with feeders filled with sunflower seeds the yards with empty feeders

Explanation:

In an experiment, the control group is the group that does not receive the treatment (in this case, the treatment is filling bird - feeders with sunflower seeds). The yards with empty feeders are not given the treatment and are used for comparison to see if the sunflower seeds in feeders attract more woodpeckers.

Answer:

the yards with empty feeders