Turner often saw woodpeckers perched in trees in his backyard, but he never saw
them at his bird feeders. Turner usually
filled his feeders with sunflower seeds. He
wondered if he could attract woodpeckers
by adding a different type of food to the
feeders.
To test this idea, Turner gathered eight
identical bird feeders. He filled four with
sunflower seeds. He filled the remaining
four feeders with crushed peanuts. Turner
then placed the bird feeders in his
backyard. Over the next five days, he
counted the number of woodpeckers that
visited each bird feeder each morning.
a woodpecker at a bird feeder
Which of the following was an independent variable in this experiment?
the type of food used in the bird feeders
the number of woodpeckers that visited the bird
feeders

      n

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.