This ability to make copies of DNA, as simple as it sounds, has transformed our world. DNA的这种复制能力听起来很简单，却改变了我们的世界。 Scientists use it every day to detect and address disease, to create innovative medic
THE PRESIDENT: I want to thank an extraordinary group of American citizens who have served our country as members of my Cabinet. Everybody around this table here could have taken the easy road and sta
