1.   He threw a grenade that penetrated the wall of the building and exploded inside.

2.   And because infrared transmissions do not penetrate walls, there is no chance of interference or overlap in neighboring rooms.

3.   A criminal investigation forges onward, the detectives trying to penetrate the wall of silence.

4.   First, though, Chen must penetrate a wall of mainland Chinese resistance.

5.   I wait until the next day and start over and I never penetrate the wall.

6.   Nonetheless, drugs still penetrate prison walls.

7.   Pipes ruptured as the assailants set off explosions that penetrated the walls of the two-story building.

8.   Several of the deaths from drive-by shootings last year occurred after bullets penetrated house walls.

9.   The concern is gradually penetrating the walls of Capitol Hill.

10.   The grenade penetrated the wall at the sixth-floor level and destroyed a large copy machine inside.