TOEFL Listening: ETS-TOEFL听力机经 - 95A4K944EW1CGUXGP$

What does the professor imply about the results of the second caching study? A. They suggest that scrub jays cache food to meet anticipated needs. B. They contradict the results of the first caching study. C. They show that regular feeding discourages caching. D. They show that scrub jays cache more efficiently when observed than when alone.