Final answer:
To combine the given sentences, use the past perfect tense. The combined sentence is 'He had been in the habit of smoking, but he no longer smokes.'
Step-by-step explanation:
The sentence 'He was in the habit of smoking' is in the past tense. To combine these sentences, we can use the past perfect tense. The combined sentence would be: 'He had been in the habit of smoking, but he no longer smokes.'
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