preoccupy [ pre- = beforehand 事先；occupy v. 占据→]v. ① occupy beforehand 先占，先取 /Our favourite seats have been preoccupied. 我们的最想要位子巳被人家先占去了。②take up all the attention 使全神贯注，迷住 / She was preoccupied with the thoughts of getting to London. 她一心想着去伦敦的事儿。 preoccupation n. 先占，先取；全神贯注

prepay [ pre- = beforehand 预先；pay v. 支付→]v. pay in advance 预付 / He prepaid the shipping charges to make sure the package would arrive on time. 他预付了货船运费以保证货包按时到达。

prepayable a. 可预付的

下面回过头来分析几个由原生前缀pre-与词根结合的词。

preamble [pre- = before 前，amble = to walk 走“walking before 居于前面”→] n. introduction to a speech or writing 开场白；序言/ This is a long preamble of a tale. 这个故事说来话长。

preambulate v. 作序言或绪论

precede [pre- = before 前；ced = to go 走；-e →] v. go or come before in order, place or time先于；位于…之前；比…领先/ She preceded me into the room. 她比我先进房间。

precedence n. 领先；在先；优先 

precedent a. 在前的；优先的 n. 先例