TOEFL Reading: ETS-TOEFL阅读机经 - 5954P8185B055E74L$

Paragraph 2 supports which of the following statements about comet size? A. The size of a comet is affected by the addition of gases absorbed as the comet passes the Sun. B. The size of a comet's tail is less variable than the size of its coma. C. The coma of most comets is smaller than the Sun. D. The size of a comet cannot be accurately determined until it nears Earth.