TOEFL Listening: ETS-TOEFL听力机经 - V3HAGG913794Y3FNP$

The professor mentions steps that shipping companies could take to reduce noise. What does the professor imply about these steps? A. They were developed by experts outside the shipping industry. B. Most scientists doubt that they are technologically feasible. C. They would only be effective at a low cruising speed. D. Some of them could save shipping companies money.