1. reduce vt.减少，缩减
The price of these shoes has been reduced since the New Year’s Day.
The new bridge reduces the traveling time from 50 minutes to 15 minutes.
reduce to减少到，使……变为（更小尺寸）
reduce by减少了，（以……的比例）减少
拓展：
reduction n.缩减，减少，降低
make a reduction打折扣
at a reduction of打了……的折扣
考点例题：
We can _________________ in price of the hat for you because we are now making a reduction.
2. certain adj.确定的；某一个
She is certain to do well in the examination.
It’s about certain that the government will lose the next election.
A certain person called on my yesterday.
拓展：
for certain 肯定地；确凿地（certainty n.）
