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[00:00.00]在线英语听力室( www.tingroom.com )友情制作 [00:03.81]1999 Passage4 [00:07.51]When a Scottish research team startled the world [00:10.54]by revealing 3 months ago [00:12.61]that it had cloned an adult sheep, [00:14.94]President Clinton move
OK, one more thing, if I can even get more bizarre. 另外还有一件事是更难以想象的 Since virtually all the mass of an atom is in the nucleus 既然事实是原子的全部质量集中在原子核, now, there is some amount of mass in th
Paracrine - cell messengers also called cytokines which are locally acting, produced by neighbouring cells or the extracellular matrix, as distinct from as distinct from endochrine or hormonal messeng
This is Scientific American's 60-Second Science. I'm Steve Mirsky, got a minute? Neandertals were our closest relatives. And now we know a lot more about them. Because researchers have for the first time sequenced a complete Neandertal genomethat of
Questions 12-20 The elements other than hydrogen and helium exist In such small quantities that it is accurate to say that the universe somewhat more than 25 percent helium by weight and somewhat less than 25 percent hydrogen. Astronomers have measur
By Melinda Smith Washington 17 July 2007 Antibiotics are designed to fight a multitude of bacterial infections. But some infections -- such as those in the urinary tract -- have become resistant to many antibiotics. VOA's Melinda Smith reports on a r