21.   However, the Arizona study raises questions.

22.   Nancy Sutley, a senior policy adviser for the U.S. Environmental Protection Agency, said the study raised questions about the effectiveness of the underground tank regulations.

23.   Now, a rat study has raised the possibility that the radiation might adversely affect learning and memory.

24.   Now a new study raises questions about the best way to diagnose one of the best-known RSI diseases, carpal tunnel syndrome.

25.   On the supposed rarity of women impregnated by rape, a recently released study should raise more than a shadow of doubt.

26.   One leading critic of this research said the new rat study raises even more questions about administering ketamine to induce psychotic symptoms in people.

27.   Recent studies also raised concerns about the practice of heading soccer balls, especially in youth leagues.

28.   Recent studies have raised a cloud over such drugs, however, saying they may promote adverse cardiovascular events, gastrointestinal bleeding, and even colon cancer.

29.   She said that this study had raised wide concern in the travel-medicine community.

30.   The Census Bureau study raises those kinds of questions.