题目选项分析

Scientists have identified an asteroid, 2000 BF19, that is about half a mile wide and, if it would strike Earth, part of the planet could experience a tremendous amount of damage but it would probably not cause planetwide destruction.

Scientists have identified an asteroid, 2000 BF19, that is about half a mile wide and that, if it were to strike Earth, could do tremendous damage to part of the planet but would probably not cause planetwide destruction.