at seven o’clock at a bus stop at first at last at (mid)night at once立刻 at times不时

at noon at the same time at present目前 at the end of在…末尾 be good at擅长 not…at all arrive at at least至少 at the moment此刻 look at knock at敲 point at 指着 laugh at aim at瞄准；针对 at the age of 在…岁 be amazed at= be surprised at对…感到惊奇