I bet I can go one hour in your class this morning and not feel a thing!
我打赌我今天上午到的健身班运动一小时之后丝毫不累。
Know something like the palm of one's hand.
熟知其事,了如指掌。
But the station master was adamant: rules could not be broken and she had to watch that train disappear towards her destination while she was left behind.