He had a still, almost blank face in repose.

他休息时面部平静，几乎毫无表情。

《柯林斯英汉双解大词典》

There he stuck his tongue out, opened his mouth, pursed his lips and moved his fingers, then watched, with a blank face, for the infants' reactions.

之后实验者一脸平静地看着婴儿，等待他的反应。

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In a moment, however, his face grew blank, and he fell to hunting round in a circle with pleading whine.

可是，过了一会儿，他的脸变得神色茫然，他开始哀嚎着，打着圈儿寻找起来。

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The senior policeman came out, and I searched his blank face for clues.

NEWYORKER: Cell One

At the time of the first plane crash, Bush was visiting a Florida classroom and his seemingly blank face and nonexistent sense of urgency spurred talk by critics across the country.

FORBES: Bush Discusses Controversial Reaction to 9/11

"If you'd have said about 10 years ago to a chemist: 'Let's have some soap that responds to magnets', they'd have looked at you with a very blank face, " said co-author Julian Eastoe of the University of Bristol.

BBC: Magnetic soap could help in oil spill clean-ups