at the same time

但是，然而

at random, at regular intervals, at sb's disposal, at sb.'s heels, at sea, at sight of, at stake, at table, at that, at that rate, at the back of, at the beginning of, at the best, at the cost of, at the expense of, at the instance of, at the latest, at the mercy of, at the moment, at the rate of, at the thought of, at the worst, at this rate, at times, at work, at worst, AT&T, at-home, atavism, atavistic, ate, atelier, atheism, atheist, atheistic, Athelney, Athens, athlete, athlete's foot, athletic,