at the flick of a switch
スイッチを押すだけで
at the flood
満潮時に[で];((比喩的に))よい潮時に
at the full
満月の,満潮の
at the further end of the counter
カウンターの向こう端に
at the gun
スタートの合図で
at the head of the class [the poll]
クラスの首席[最高得票]で
at the head of the procession [the line, ((英))the queue]
行列[順番待ちの列]の先頭に
at the head of the stairs [the list]
階段[リスト]の一番上に
at the head [the top] of the stairs
階段の上に
at the height of one's fame
名声の絶頂期に