Nature staff discuss some of the week’s top science news.
DENVER—The Global Positioning System is one of the few space programs that touches nearly every human life, and the stewards of the satellite navigation network are eager to populate the fleet with the latest and greatest spacecraft.
。同城约会是该领域的重要参考
所谓宋朝重文抑武的国策，其实见仁见智，说法很多，争议也比较大。它应该被视为一种结果性的文化现象或政治现象，而不是一开始就非常明确的国策。它是一种在五代时期形成的政治共识，被潜移默化地运用到国家政治当中。
But fancy type system features aren't free:
Off-the-shelf vs. bespoke