1.EAR GROWS ON MOUSE'S BACK
2.AIR POLLUTION
3.WHAT MADE OUR ANCESTORS WALK UPRIGHT?
4.WHY DO BIRDS SING?
5.WORLD HUNGER
6. SCIENTISTS HELP SAVE PANDAS
7.HEAT TREATMENT TESTED ON AIDS PATIENTS
8. HERMIT CRABS LEARN WHAT NOT TO EAT
9.SHOULD WE MOVE THE MOON?
10.FROGS TAP OUT LOVE TUNES
11.HOW SAFE IS IRRADIATED FOOD?
12.WHERE DO EARTHQUAKES OCCUR?
13.WHAT IS A STAR?
14.SONAR
15.FOSSILS——THE EVIDENCE OF EARLIER HISTORY
16.SOLAR ENERGY
17.WHY IS THERE MORE SEA THAN LAND ON THE EARTH'S SURFACE?
18.THE COMPASS
19. VITAMINS
20.WHEN WAS THE STETHOSCOPE INVENTED?
参考译文
Key to the Exercises
鄂公网安备 42010302001612号 