B-1's would penetrate defenses at 650 miles an hour about 200 feet above the ground.

Trying to penetrate her defenses was not yet an option for me.

Still, he did not penetrate her defenses, though she had to shift ground more than once.

No one could penetrate her defenses unless she allowed it.

Soon after we got here there were a number of attempts to penetrate our defenses.

Now all we need is a way to penetrate their defenses.

Pitt could see his words were penetrating her weak defenses.

I'm terrified they will penetrate his defenses and kill him.

An initial assault penetrated the city's defenses and reached its airport.

The hunter knew at once that more guards would be about; he probably had penetrated their defenses without even seeing them.