By measuring how fast these stars were moving, he could prove if there really was a black hole at the center of an active galaxy. I picked a galaxy nearby which is called NGC 1068, an active galaxy, w

发表于:2018-12-07 / 阅读(330) / 评论(0) 分类 超大质量黑洞

Quarter 25分硬币 A quarter is an American or Canadian coin. quarter是指美国或加拿大的一种硬币。 How much is a quarter? 这种硬币值多少钱呢? A quarter is equal to 25 cents. 它等价于25分。 It is worth one fourth of a do

发表于:2018-12-13 / 阅读(34) / 评论(0) 分类 与美国小学生一起学英文第5册

Heres what scientists think happened, oh, about a hundred million years ago. There was this three-star system. The three linked stars were strolling through the galaxy but got too close to the giant black hole at the center. The hole swallowed one of

发表于:2018-12-24 / 阅读(32) / 评论(0) 分类 Scientific American(七)月

Hi, I'm Carl Azuz. Welcome to this Columbus Day edition of CNN Student News! We'll be talking more about Columbus Day in just a couple minutes. But first, we're reporting on a breakthrough in Chile. And we mean that literally. A hole big enough to re

发表于:2019-01-08 / 阅读(58) / 评论(0) 分类 CNN2010年(十)月

Diameter 直径 A diameter is a straight line inside a circle. 直径是圆内的直线。 Can any straight line in a circle be a diameter? 圆内的任何直线都是直径吗? No, its two ends must meet at two different points on the circle. 不是

发表于:2019-01-10 / 阅读(39) / 评论(0) 分类 与美国小学生一起学英文第9册

台湾籍旅美老师今天交给我们的句子是: In fact, a black hole with the diameter of a nickel would be slightly more massive than the Earth. It would have a surface gravity a billion billion times greater than our planet currently does. 事

发表于:2019-03-05 / 阅读(95) / 评论(0) 分类 留美老师带你每日说英文