题目

  Styrofoam is a plastic with a bad reputation.   It cannot be recycled without releasing(释放) dangerous  61  (pollute)into the air. The U. S. Environmental Protection Agency  62 (say) it is the fifth largest creator of dangerous waste.   Scientists from the U.S. and China have discovered that mealworms can digest plastic. One mealworm can digest a pill-sized amount of plastic a day. Study co-author Wei-Min Wu says that in 24 hours, the plastic  63  (turn) into carbon dioxide. Are the worms hurt by  64  (eat)plastic? The study found that worms eating Styrofoam were as  65如图所示，排球离开手后仍在空中继续飞行，不考虑空气阻力，在图中画出排球受力的示意图．