儿童占世界人口的很大一部分。

Children make up a large ___proportion of the world's population.

这个班级由大致相等比例的男性和女性组成。

The class consists of men and women in roughly equal ___proportions.

相当一部分受访者（80%）表示他们对危险的道路和高峰时段的排队不满，而且在租到安全的房子方面也遇到困难。

A significant ___proportion of the respondents ___80% said that they are not pleased with dangerous roads and the queues during the rush-hours and they also encounter difficulties in finding a safe house to rent.