1. Owe relative to what lag behind to economy develop for the area, this since is challenged austerely, it is rare development opportunity. 对于经济相对落后的欠发达地区来说，这既是一次严峻的挑战，又是一次难得的发展机遇。
2. But 2 0 century after 70 time, manpower capital theory got be challenged austerely, world each country all appeared a series of education issues and the social issue that its bring. 但是 2 0世纪 70年代以后 ，人力资本理论受到了严峻的挑战 ，世界各国均出现了一系列教育问题及其带来的社会问题。
3. Brothels are illegal in Canada, but the country's prostitution laws have recently been challenged in the court as unconstitutional. 在加拿大卖淫是非法的，但是该国卖淫法律最近在法院却遭到“不符合宪法“的质疑。
4. I challenged him to a game of chess. 我向他挑战，要跟他下一盘棋。
5. So he challenged the tortoise to another race. The tortoise agreed. 因此，再挑战乌龟再来一场比赛，乌龟也同意。
