TOEFL Listening: ETS-TOEFL听力机经 - 9Q3DO1SG53T025PJP$

What is the main purpose of the lecture? A. To discuss a challenge that must be overcome before people can live on the Moon. B. To explain some advantages and disadvantages of building a colony on the Moon. C. To question the reliability of some of the experiments conducted on lunar soil. D. To describe the discovery of an atmosphere on the Moon.