他一坐进安静的图书馆就忍不住打哈欠，看来昨晚没有睡好。
As soon as he sat down in the quiet library, he could not help yawning, so apparently he had not slept well the night before.
As soon as he sat down in the quiet library, he could not help yawning, so apparently he had not slept well the night before.