The subsolar point will cross every latitude between these two extremes exactly twice per year.
太阳直射点每年恰好两次穿越这两个极端之间的所有纬度。
2
The K21 can travel as fast as 70 kilometers per hour on paved roads and cross a river at a speed of 7.8 kilometers per hour with the help of its water-jet propulsion system.