题目选项分析

Responding to the public's fascination with-and sometimes undue alarm over-possible threats from asteroids, astronomers have developed a scale for rating the likelihood that a particular asteroid or comet will collide with Earth.

Responding to the public's fascination with-and sometimes undue alarm over-possible threats from asteroids, astronomers have developed a scale that rates the likelihood of a particular asteroid or comet that may. collide with Earth.