How to Use "observation" with Example Sentences

1. Mr allen and his colleagues made one other observation .
2. Each end is fitted with triangular observation decks .
3. In fact , it had all started with a student 's observation that I was cheerful .
4. I would like to make the additional observation that the tendency to disappoint applies to almost every single policy decision by almost every government .
5. This illusion has its origin as a chance observation .