By midnight中的by是什么词性?

这里应该是介词词性。by的用法归纳如下。by 1。介词,后可接名词性词语或短语,构成介宾结构。2。副词,后不加成分 by介词 prep。1。被,由The homework was assigned by the teacher。这些家庭作业是老师布置的。2。靠,用,通过They crossed the river by ferry。他们乘渡船过了河。3。经由;沿Ellen flew to Chicago by way of Minneapolis。艾伦经由明尼阿波利斯飞往芝加哥。4。在。。。旁边,靠近;在。。。手边I haven't got any money by me。我身边没有带钱。5。不迟于;在。。。之前We had to get there by evening。我们必须在夜晚前抵达那里。6。根据,按照How do you know he didn't act by the rules?你怎么知道他没有按规定行事?7。(表程度)相差He missed the bus by three minutes。他晚了三分钟没赶上那班公车。8。凭,对。。。(发誓)I swear by God!我对上帝发誓!9。(乘除法上)以。。。,用。。。(乘或除)Nine divided by three makes three。九除以三得三。10。以。。。计,按You'll be paid by the hour。你的工资将按时计酬。11。在。。。的时候He had to sleep by day and work by night。他只好白天睡觉,晚上工作。12。就。。。来说,关于Philip is a doctor by profession。菲利浦的职业是医生。13。(表连续或反复)逐个;逐批The teacher explained the text sentence by sentence。教师逐句讲解了这篇课文。14。由于She took my umbrella by mistake。她误拿了我的伞。