The Gurjar Pratihar Empire acted as a barrier for Arab invaders from the 8th to the 11th century. The chief accomplishment of the Gurjara Pratihara empire lies in its successful resistance to foreign invasions from the west, starting in the days of Junaid. Historian R. C. Majumdar says that this was openly acknowledged by the Arab writers. He further notes that historians of India have wondered at the slow progress of Muslim invaders in India, as compared with their rapid advance in other parts of the world. Now there seems little doubt that it was the power of the Gurjara Pratihara army that effectively barred the progress of the Arabs beyond the confines of Sindh, their first conquest for nearly 300 years.
Arab attempted to invade the Gurjar Pratihar Empire beginning in what century?
8th

However, early Christian writers who speak of the shape of the particular gibbet on which Jesus died invariably describe it as having a cross-beam. For instance, the Epistle of Barnabas, which was certainly earlier than 135, and may have been of the 1st century AD, the time when the gospel accounts of the death of Jesus were written, likened it to the letter T (the Greek letter tau, which had the numeric value of 300), and to the position assumed by Moses in Exodus 17:1112. Justin Martyr (100165) explicitly says the cross of Christ was of two-beam shape: "That lamb which was commanded to be wholly roasted was a symbol of the suffering of the cross which Christ would undergo. For the lamb, which is roasted, is roasted and dressed up in the form of the cross. For one spit is transfixed right through from the lower parts up to the head, and one across the back, to which are attached the legs of the lamb." Irenaeus, who died around the end of the 2nd century, speaks of the cross as having "five extremities, two in length, two in breadth, and one in the middle, on which [last] the person rests who is fixed by the nails."
How many ends did the cross supposedly have?
five extremities

Historically, AC motors were used for single or double speed elevator machines on the grounds of cost and lower usage applications where car speed and passenger comfort were less of an issue, but for higher speed, larger capacity elevators, the need for infinitely variable speed control over the traction machine becomes an issue. Therefore, DC machines powered by an AC/DC motor generator were the preferred solution. The MG set also typically powered the relay controller of the elevator, which has the added advantage of electrically isolating the elevators from the rest of a building's electrical system, thus eliminating the transient power spikes in the building's electrical supply caused by the motors starting and stopping (causing lighting to dim every time the elevators are used for example), as well as interference to other electrical equipment caused by the arcing of the relay contactors in the control system.
Throughout history, what type of engines were used for elevator machines?
AC motors