1、concentration
全神贯注;专心;专注
Neal kept interrupting, breaking my concentration.
尼尔不停地打断我,使得我无法集中注意力。
We lacked concentration and it cost us the goal and the game.
我们注意力不够集中,结果丢了球,输了比赛。
集中;汇集
The area has one of the world's greatest concentrations of wildlife.
这个地区是世界上野生动物最为密集的区域之一。
There's been too much concentration of power in the hands of central authorities.
权力一直过多地集中在中央机构手中。
浓度
pH is a measure of the concentration of free hydrogen atoms in a solution.
pH值是测试溶液中自由氢原子浓度的单位。
The latest data showed that global ozone concentrations had dropped several per cent over the last decade.
最新数据显示,过去10年来全球臭氧的浓度降低了几个百分点。
2、challenge
挑战;难题
I like a big challenge and they don't come much bigger than this.
我喜欢大的挑战,而所有挑战中再没有比这更大的了。
The new government's first challenge is the economy.
新政府面临的第一个难题是经济问题。
(成功地)应对挑战,迎接挑战
The new Germany must rise to the challenge of its enhanced responsibilities.
一个崭新的德国必须迎接挑战,承担更多的责任。
They rose to the challenge of entertaining 80 schoolchildren for an afternoon.
他们一个下午成功接待了80名学童。