1.The research team found that on average, today's children run one kilometre about one minute slower than their parents did three decades ago.
on average平均起来
On average, American firms remain the most productive in the world.
总体来讲,美国公司在全球范围内还是产值最高 。
2.They need to choose a range of physical activities they like or think they might like to try, and they need to get moving.
a range of一系列; 一些
They talked amiably and easily about a range of topics.
他们友好而随意地谈论各种话题 。