But if a major government gained proof of alien life, the contamination would be far worse.

Nora suspected that Lindsay faked her condition but never gained proof.

He agreed with Sayre's opinion, but he knew the difficulty of gaining proof.

For in this loss of the teakwood box, The Shadow had gained proof that forgotten factors were still at work.

"So you intend to gain proof while the president is off-world, then present it to him upon his return?"

I have suspected it for a long time, but gaining proof has been difficult.

First, we must gain concrete proof of the Freelans' true identity and purpose in order to expose them.

Again he had gained proof that the underworld was deeply concerned in the past two crimes.

Should you gain proof that he has gone crooked, you can use every effort to thwart him.

Each of us wanted to gain proof of the other's identity.