Usar "doubtfulness" en una oración

1. There was an emotional stubbornness associated with his customary doubtfulness, and this state of mind, coupled with his chagrin at having run away from them, conspired to create a situation of isolation which even Thomas himself did not fully understand

2. This suspicion that there is, this feeling about a certain concern and doubtfulness that is

3. suspicion that there is, this feeling about a certain concern and doubtfulness that is lingering on in the