重点讲解：
1. buy up 大量买进，全部买下（土地、房产或商品）；
The mention of price rises sent citizens out to their shops to buy up as much as they could.
物价上涨的说法使老百姓都涌进商店大量抢购商品=vHwe_cwk!q,p_t。
2. ups and downs 兴衰；浮沉；起落；悲欢；
We are bound to see some ups and downs along the road to recovery.
在经济复苏的过程中，我们一定会经历一些曲折起伏~BUl,s9NQ9|jZRX。
3 pick up steam (信念、计划、项目等)变得越来越重要，开始发展壮大；
Just as the presidential campaign was picking up steam, riots exploded in Los Angeles.
正当总统竞选活动的声势日益壮大时，洛杉矶爆发了暴乱3k8hdkOx2-wq*Z&Ng。
4. on the lookout for 密切留意；小心提防；
The public should be on the lookout for symptoms of the disease.
公众应当留心这种疾病的症状)f[;@H6Z~^xDGAY。