Learning key words and expressions in unit 2
1. struggle vi. 斗挣, 努力, 拼搏Eg:We should learn to struggle with difficulties.我们应该学会和困难作斗争。They were struggling to get out the burning car.                                  他们挣扎着从烧着车里往外爬。She struggled up the stairs with her heavy bags.                                  她提着沉重行李艰难地走上楼梯。[搭配] struggle against                               与…斗争，为反对…而斗争，      struggle for 为争取…而斗争
2.expand vt＆vi 使变大；伸展
eg:Metals expand when they are heated.  金属受热则膨胀。The chair ...