令人放心的研究结果表明，天文学家已经掌握了90％以上大型的小行星的空间位置，它们是一些可能导致地球表面生物物种大灭绝的，巨大的杀手行星。

The study reassuringly suggests that astronomers already know the location of more than 90 percent of the very largest asteroids — the huge planet-busters that could cause mass extinctions.

youdao

令人放心的研究结果表明，天文学家已经掌握了90％以上大型的小行星的空间位置，它们是一些可能导致地球表面生物物种大灭绝的，巨大的杀手行星。

The study reassuringly suggests that astronomers already know the location of more than 90 percent of the very largest asteroids — the huge planet-busters that could cause mass extinctions.

youdao