1·They can go about 25 miles per hour.
它们每小时可以走约25英里。
2·It can fly at a speed of about 200 miles per hour.
它能以每小时200英里的速度飞行。
3·According to most calculations, race walkers moving at a pace of six miles per hour would burn about 800 calories per hour, which is approximately twice as many as they would burn walking, although fewer than running, which would probably burn about 1,000 or more calories per hour.
根据大多数计算结果，竞走者以每小时6英里的速度前进时，每小时会燃烧大约800卡路里，尽管比跑步时燃烧的热量要少，但这大约是他们走路时燃烧热量的两倍，跑步时每小时可能会燃烧大约1000卡路里或更多。
4·They had to deal with winds as fast as 75 kilometers per hour.
他们必须应对风速高达每小时75公里的大风。
5·They can move over 200 miles per hour and cause a lot of damage.
它们可以以每小时200英里的速度移动，造成巨大损害。
6·It flies as high as 3000 meters, and as fast as 100 kilometers per hour.
它的飞行高度可达3000米，速度可达每小时100公里。
7·Plants that were in no immediate danger gave out less than one ultrasonic sound per hour.
那些不受直接威胁的植物每小时发出的超声波不到一次。
8·We would fly at 480 kilometres per hour, avoiding traffic lights, busy roads and speeding tickets.
我们能以每小时480公里的速度飞行，避开红绿灯、拥挤的道路和超速罚款单。
9·It flies at 240 km per hour at a height of 4,500 meters in the sky.
它在4500米的高空以每小时240公里的速度飞行。
10·In nine minutes, the probe had to reduce its speed from 20,000 km per hour to zero, landing from 125 km above Mars.
在9分钟内，探测器必须将速度从每小时2万公里降至零，从火星上空125公里处着陆。