TOEFL Reading: ETS-TOEFL阅读机经 - 8JPQ1219F575719NL$

All of the following questions can be answered based on the facts presented in paragraph 1 EXCEPT: A. Do any comets travel to regions of space beyond our solar system? B. Do most short-period comets enter the inner solar system? C. What are comets composed of? D. Why are comets regarded as among the most unpredictable bodies in the solar system?