TOEFL Listening: ETS-TOEFL听力机经 - FDP14C513I1A438UP$

Why does the professor describe some characteristics of wild wheat plants? A. To show one reason why humans began to domesticate plants B. To illustrate how ancient people made flour C. To explain why the spikelets of wild wheat do not fall off the stalk D. To show that wild plants are less nutritious than domesticated plants