'Fundamental competence': Economy brings Trump’s 'political risks into focus' — here's how
The U.S. Commerce Department delivered some bad economic news on Wednesday, April 30: the United States' gross domestic product (GDP) contracted by 0.3 percent during the first three months of 2025.This was the first GDP report released during Donald Trump's second presidency, and it comes at a time
New F-15 Streak Eagle Photos (Reblog)
现在在美国空军国家博物馆的F-15 Streak Eagle照片。下载此处或这里或这里（14 MEGS）
Curious isolation: New butterfly species discovered
在加拿大落基山脉的心脏地带，多年来，我们的科学雷达在我们的科学雷达下一直在悄悄地飞行。翼展为一英寸到一英寸半，翅膀在上面是棕色的，棕色的棕色，下面是黑色斑点，长期以来人们认为这一人口属于半月式毛发（Satyrium semiluna）。然而，艾伯塔省沃特顿湖国家公园的布拉基斯顿风扇的孤立的头条蝴蝶现已被公认为是一种独特的物种：satyrium culiosolus或奇怪的孤立的hialestreak。
Get Motivated to Learn with Khan Academy’s New Streaks and Levels Features
作者：Daniel De Angulo，Khan Academy 高级产品经理 大家好！Khan Academy 很高兴宣布推出两种新机制，旨在让学习变得更有趣、更有动力：连续性和等级！连续性和等级旨在促进和庆祝一致性，激励学习者每年至少将一项技能提高到熟练或更高水平 […]The post Get Potivated to Learn with Khan Academy’s New Streaks and Levels Features 最先出现在 Khan Academy Blog 上。
