重点讲解：
1. at least （数量）至少，不少于；
Every time she travels on the bus it's delayed by at least three hours.
每次她乘公车出行都至少耽搁3个小时K6691x.hOZJSxIk9)G|A。
2. connect to 把…联系起来；
Dylan's participation in the massacre was impossible for me to accept until I began to connect it to his own death.
直到我将迪伦的死和校园枪击案联系起来之前，我无论如何不能接受他参与在其中的事实3]c+cWldkeXqj&rR^I。
3. inject into 添加；注入；
The technique consists of injecting healthy cells into the weakened muscles.
该技术是把健康细胞注射到衰弱的肌肉里面K9-,Qe8GU4|A。
4. up to 高达；多达；
Up to twenty thousand students paid between five and six thousand dollars.
多达20,000名学生支付了5,000到6,000美元(N.2pkfKy_。