1.   It was a risky operation, but might buy more time.

2.   And it has continued to perform less risky operations in which adults donate parts of their livers to children.

3.   And why does Defense Secretary William Perry think this risky operation serves U.S. national interests?

4.   A risky operation saved his life, but the right side of his face was permanently paralyzed and his voice forever altered.

5.   Caesareans remain risky operations that ought to be done only to maintain the well-being of mother or infant.

6.   Certainly it is a risky operation.

7.   Indeed, even a less risky operation cannot be required.

8.   Launching helicopter gunships into the battle will be a risky operation.

9.   Mark Wahlberg is Capt. Leo Davidson, an astronaut on a space station who trains chimps to fly vessels for risky operations.

10.   The risky operation took an entire day.