重点讲解：
1. step up 增加（数量等）；提高（速度、强度等）；
例句：The firm must step up production this year.
这个公司今年必须提高生产。
2. participate in 参与；参加；
例句：We both participated in the experimental work.
我们俩都参加了这次实验工作。
3. wade into 介入，干涉；
例句：They don't just listen sympathetically, they wade into with remarks like, 'If I were you...'.
他们不是只同情地倾听，而是还时不时地插话进来：“如果我是你…”
4. due to 由于；因为；
例句：The town was blacked out due to power failure.
这个城镇由于停电变得一片漆黑。
