TOEFL Listening: TPO-TOEFL阅读TPO - 231GS4M43_SHEW79N$

According to paragraph 4, what do the 2003 Global Surveyor data suggest about Mars? A. Ancient oceans on Mars contained only small amounts of carbon. B. The climate of Mars may not have been suitable for the formation of large bodies of water. C. Liquid water may have existed on some parts of Mars' surface for long periods of time. D. The ancientoceans that formed on Mars dried up during periods of cold, dry weather.