第二节：完形填空（共20小题；每小题1.5分，满分30分）
阅读下面短文，掌握大意，然后从16-35各题所给的A、B、C、D四个选项中，选出最佳选项。
The history of modern water pollution goes   16   to February 28, 1931, when Mrs. Murphy   17   over her backyard fence and said to Mrs. Holbrook, “You   18   those shirts white?” Mrs. Holbroak was   19   to admit they were as white as she could get them  20   that ordinary soap.
“What you should use is this Formula Cake Soap which   21   against the dull grey look that the family wash   22   had. ”
Doubtful   23   adventurous, Mrs. Holbrook tried the Formula soap,   24   did take the grey out of her husband’s shirts. But what she didn’t know was that the water eventually was   25   into the Blue Sky River, killing two fish.
Three years later Mrs. Murphy was   26   her shirts and Mrs. Holbrook said, “How did you ever get your collars so   27  , surely not with Formula?”
“Not ordinary Formula. But I did with Super Fortified Formula. You see, it attacks dirt and destroys it. Here, try some   28   your shirts.”
Mrs. Holbrook   29   and discovered her husband’s shirt collars turned pure white. What she could not possibly know was that it turned the river water pure white as   30  .
Six months later, the Blue Sky River was   31   a health hazard. One day as Mr. Holbrook was walking home from work.，he accidentally   32   the Blue Sky River, swallowed a   33   of water and died immediately. At the funeral service the minister said, “You can say anything you want   34   Holbrook, but no one can deny he had the   35   shirts in town.”
16. A. straight              B. down                   C. off                 D. back
17. A. 1eaned             B. 1eapt             C. stretched         D. sloped
18. A. name                B. make             C. get                 D. call
19. A. shamed              B. ashamed          C. shameful            D. shameless
20. A. without              B. with                    C. from               D. by
21. A. protects                 B. promises           C. guarantees          D. ensures
22. A. seldom               B. never             C. possibly            D. always
23. A. but                     B. and               C. or                 D. though
24. A. it                   B. she               C. which              D. that
25. A. left                     B. emptied            C. reached             D. rushed
26. A. hanging up        B. hanging on         C. putting up           D. putting on
27. A. dirty                B. soapy              C. grey               D. white
28. A. for                     B. to                 C. on                D. at
29. A. refused           B. did                C. hesitated            D. understood
30. A. snow             B. expected            C. usual              D. well
31. A. stated             B. published         C. recognized           D. declared
32. A. fell into                 B. swam            C. crossed over         D. drowned
33. A. mouthful            B. drop               C. glass              D. drink
34. A. to                      B. about               C. as to              D. as for
35. A. best              B. oldest               C. cleanest            D. dirtiest