TOEFL Reading: ETS-TOEFL阅读机经 - 7I4J531CZ1SIG347L$

Select TWO answer choices that according to paragraph 4 describe how a comet changes as it travels away from the Sun. To receive credit, you must select TWO answers. A. It loses its metallic and stony particles. B. It loses all the material that was in its tail. C. Its orbital period becomes shorter. D. The gases that were in its coma recondense.