Which preposition to use with blankly

in Occurrences 3%

" Mr. Smith, scratching his smooth-shaven chin and staring blankly in front of him, said that he was glad to hear it.

at Occurrences 2%

" Someone called him from the door, and he turned away, leaving me staring blankly at nothing.

for Occurrences 2%

He turned quickly and looked at his nephew blankly for a moment, and then his left eyebrow went up.

as Occurrences 1%

He was staring as blankly as ever.

than Occurrences 1%

" He stared at me more blankly than ever when I let this out on him, and suddenly he laughed.

through Occurrences 1%

He sat up and stared at her blankly through his drenched eyes.

Which preposition to use with  blankly