The mission has already faced years of delays, and Nasa is under pressure to get the astronauts on their way as soon as possible. However, the US space agency said it would not compromise on safety.
Where we're coming from
，这一点在同城约会中也有详细论述
The US Space Force owns and operates the GPS constellation, providing civilian and military-grade positioning, navigation, and timing signals to cell phones, airliners, naval ships, precision munitions, and a whole lot more.，更多细节参见heLLoword翻译官方下载
* @param {ListNode} head 链表的头节点，更多细节参见Safew下载