41.   Researchers then compared the effects.

42.   Researchers compared the risks of contracting the disease through contacts with live poultry, preparing poultry dishes and eating chicken a week before the patients fell ill.

43.   Researchers then compared those figures for youths with the number of underage people restricted from buying tickets.

44.   Researchers compared how closely the performance of one twin in each pair matched the performance of the other.

45.   Researchers compared IVF families, IVF families that used donated sperm, families with naturally conceived children and those with adopted children.

46.   So the researchers compared clomipramine with another drug, desipramine, which had similar side effects but does not affect serotonin.

47.   Some volunteers also will take a bird count in different habitats, from pine forests to agricultural areas to neighborhoods, so researchers can compare how birds are faring.

48.   The researchers then compared the long-term effects on their breast cancer.

49.   The researchers compared the progress of those patients with the results for patients in clinical trials.

50.   The researchers compared the two approaches by measuring levels of a blood protein called prostate-specific antigen for years after treatment.