My dad will be back ___two o'clock

My dad will be back ___two o'clock I don't think my father will be back() 3o'clock this afterno 在句子“My father will be back after 3 o'clock.”中为什么不能in用代替after we will be back/ in / six o'clock.可是答案是at It's eleven o 'clock .He will be back at twelve .= my father will come back at three o'clock in the afternoon同义 ( )10.My father will come back at 10 o’clock ______of June 1 The film will be on_____eight o'clock ___ten o'clock. o'clock will at home My seven He says he will be back —— 10 o'clock.为什么 用 at 而不用in? i must be at work at 10 o'clock.My employer will confirm tha He will come back after ten o'clock同义句