Hi, everybody. It's been a challenging couple of weeks. The shootings in Minnesota and Baton Rouge; the protests; the targeting and murder of police officers in Dallas – it's left all of us st

66 million years ago, a much larger object hit the Earth, causing a massive extinction. 六百六十万年前，一个更大的物体撞击地球，造成了物种大灭绝。 75 percent of plant and animal species were lost, including, sadly, the dinosaurs.

And this is a form of learning called active learning, 这是一种学习形式叫做主动学习， and really promoted by a very early paper, in 1972, by Craik and Lockhart, where they said and discovered that learning and reten

I’m here in Detroit visiting workers at a GM plant in the heart of a resurgent（复活的） American auto industry. And I brought a guest with me – President Lee of South Korea. We’re here b

REMARKS BY THE PRESIDENTON REDUCING SPENDING IN THE BUDGET Dwight D. Eisenhower Executive Office BuildingRoom 350 10:42 A.M. EDT THE PRESIDENT: Good morning, everybody. All across this country, Americ