[they] felt life in Moscow insupportable in the heat and dust, when the spring sunshine was followed by the glare of summer,
Leo Tolstoy. Anna Karenina
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then there was an expression of almost insupportable haughtiness in her bearing and countenance.
Charlotte Brontë. Jane Eyre (1847)
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There was a melancholy wind, and the marshes were very dismal. A stranger would have found them insupportable, and even to me they were so oppressive that I hesitated, half inclined to go back.
Charles Dickens. Great Expectations (1861)
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He was insupportable when he imagined he had caught a chill. Liza had continually to interrupt her inquisitive observations and run from the verandah to his room. At dinner-time she had to put on mustard plasters.
Anton Chekhov. Love and Other Stories
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he hoped, in a few weeks, both empires would be freed from so insupportable an encumbrance.
Jonathan Swift. Gulliver's Travels Into Several Remote Regions of the World (1726)