Light from the Past

When you stand and look at the stars, you are really looking at past history. The light from Alkaid, the end star in the handle of the Big Dipper, has taken about 210 years to 32 ______ your eyes. If Alkaid stopped

33 ______ today, people on earth would still see it 34 ______ about 210 years. Some of the stars you see here tonight may have stopped existing several thousand years ago. The light from some 35 ______ stars right now will not be seen on earth until thousands, or even millions, of years from now!

It’s 36 ______ breathtaking, and it 37 ______ to the great mystery about the nature of light. Think about water waves. They get smaller and smaller in amplitude as they travel. Their energy is lost in friction among the water molecules. Think of sound waves in air. They too get weaker and weaker because of friction among the air molecules.

But light waves stop only if they strike something, and their energy is transferred 38 ______ another form. Otherwise, they can go on and on, at the same terrific speed, with no loss of energy, forever!

32. 1) approach 2) reach 3) hit 4) achieve

33. 1) burning 2) flashing 3) blushing 4) shining

34. 1) after 2) through 3) for 4) at

35. 1) farewell 2) faraway 3) far 4) fair

36. 1) quit 2) quick 3) quiet 4) quite

37. 1) enlarges 2) increases 3) adds 4) multiplies

38. 1) into 2) onto 3) for 4) at