从每小题的A、B、C、D四个选项中，选出可以填入空白处的最佳选项
The rapid growth in skyscrapers worldwide, most of which have large windows, has led to a high demand for window washers. Though the job is well-paid, it is dangerous and accidents are not uncommon. However, if Israel-based start-up Skyline Technologies has its way, the dangerous job may soon be done by Ozmo, an intelligent window cleaning robot, with humans supervising from the safety of the ground.
Much like humans, Ozmo, sitting on platforms hanging from the buildings, uses its arms and brushes to clean the dirt on the glass. A 3D map of the building's surface programmed into its system allows the robot to skillfully deal with any obstacle it is likely to meet, as it moves up and down the buildings. The robot will self-correct and move around every obstacle that it might have met so as not to break a window.
Unlike present window washers, the robot cleaner does not require soap to clean the glass. Instead, it uses distilled （蒸馏的） water to do the job. Yaron Schwarcz, CEO of Skyline Robotics explains, "We are environmentally friendly."
Ozmo is also expected to be much more efficient than its human counterparts. While it presently takes three cleaners 480 hours each to clean windows of a 40-storey glass building, the robot will be able to do it in 80 hours. However, unlike other robots, Ozmo will not replace human workers, and only make their jobs safer by making them supervisors, who will be controlling the operation from the safety of the ground.
Whether Ozmo, which is still being tested, does as good a job as humans is not clear. If things go well, its creators have much bigger ambitions for Ozmo. Schwarcz told Forbes Magazine, "Window cleaning is justthe tip of the iceberg. We plan to replace all tasks that are dangerous and dirty."