New Delhi, Aug. 19 -- The Union education ministry on Tuesday said the National Testing Agency (NTA) has removed 600 subject experts, is introducing a four-tier question-paper checking system, and will relocate its headquarters from Okhla to central Delhi, as part of sweeping overhaul following repeated paper leaks and question-paper errors over past two years. The disclosure came a day after ministry directed NTA to "fix accountability." P9...