题目选项分析

In late 1997, the chambers inside the pyramid of the Pharaoh Menkaure at Giza were closed to visitors for cleaning and repair because moisture exhaled by tourists had raised the humidity within them to such levels that salt from the stone was crystallizing and fungus was growing on the walls.

In late 1997, the chambers inside the pyramid of the Pharaoh Menkaure at Giza were closed to visitors for cleaning and repair because tourists were exhaling moisture, which had raised the humidity within them to levels such that salt from the stone would crystallize and fungus was growing on the walls.