模拟试题

The once radical notion that birds descended from dinosaurs——or may even be dinosaurs， the only living branch of the family that ruled the earth eons ago——has got stronger and stronger since paleontol...

　As you read this， nearly 80，000 Americans are waiting for a new heart， kidney or some other organ that could save their life. Tragically， about 6，000 of them will die this year——nearly twice as many ...

　Plowing through the New York Times on a recent Sunday， I read in the Metro Section that infertile couples in the market for smart-kid genes regularly place advertisements in the newspapers of their o...

It has long been known that the rate of oxidative metabolism (the process that uses oxygen to convert food into energy) in any animal has a profound effect on its living patterns. The high metabolic r...

　Scientists have known since 1952 that DNA is the basic stuff of heredity. They’ve known its chemical structure since 1953. They know that human DNA acts like a biological computer program some 3 bill...

On this one point George W. Bush and Al Gore would agree： our schools need more Marilyn Whirrys. For 35 years， Whirry has inspired high school students to think deeply about great literature and to us...

By modern standards， the hostile summit of Mount Llullaillaco， in the Argentine Andes， is no place fro kids. The ancient Inca saw things differently though， and so it was that one day， some 500 years ...

After stepping down this summer as the head of the EPA， the embattled Christine Todd Whitman is once again in the hot seat. This time it’s over her role in the downplaying of health hazards for New Yo...

I am a hip-hop head for life. I have tagged my moniker—— “kepo1”——on walls; break-danced on cardboard; bumped elbows with fellow hip-hoppers at legendary clubs like The Rooftop， Union Square and Latin...

　Imagine asking a presidential candidate to sit down for a sensitivity session on gay and lesbian issues. That’s exactly what we did last week in Austin， Texas. George W. Bush invited us， a dozen gay ...