放射性同位素

But initially Ken Livingstone, London's leftist mayor, said it was fine for Mohammed Kamel Mostafa to work on the Tube—only to back down later, saying the young man had hidden his past.

但在最初，左翼的伦敦市长肯·利文斯通说过，穆罕默德·卡迈勒·穆斯塔法在伦敦地铁系统工作是合适的——其后他也只是反悔说，这位年轻人当初隐瞒了其履历。