Translation of "Roughly" in Chinese

Asia is roughly four times the size of Europe.

亚洲的大小约四倍于欧洲。

Think real hard, roughly where did you lose it?

你想清楚，大概在什么时间什么地方掉的？

Roughly speaking, there were about 30 people in the bus.

公车上大约有三十几个人。

The population of the country is roughly estimated at 50,000,000.

這個國家的人口粗略估計是五千萬左右。

Each year, the campus avoids using roughly 3 million plastic bottles.

这样学校里可以少用差不多三百万的塑料瓶

In the US, roughly 40% of the food we produce never gets eaten.

在美国，生产的食品大概有40%不会被吃掉

My chinese is far from perfect, but I can roughly understand everything he is saying.

我的漢語並不完美，但能大致聽懂他所說的。