Spondylosis is Osteoarthritis, so lumbosacral spondylosis would be osteoarthritis in the lumbosacral area of the spine. Here is a link to an article about cervical osteoarthritis, which is similar. http://www.webmd.com/osteoarthritis/guide/cervical-osteoarthritis-cervical-spondylosis.
MOTOR CONTROL CENTER. A motor control center consists of one or more vertical metal cabinet sections with power bus and provision for plug-in mounting of individual motor controllers. Very large controllers may be bolted in place but smaller controllers can be unplugged from the cabinet for testing or maintenance.
The Pentagon was the world's largest office building for a while. The Vehicle Assembly Building, where NASA puts together its rockets, is pretty amazing. It was built in 1966 and was only supposed to last 10 years. It's still in use. Burj Khalifa is currently the tallest man-made structure in the world. You might find this list interesting: List of largest buildings in the world.