You are so absorbed watching the movie casablanca with friends that when two people ask if you want a snack, you do not even hear them. when reminded of this later, you realize that you were aware of the movie to the exclusion of everything else. this could be termed a mild:

This could be termed a mild dissociative experience.
It means that you are either mildly or greatly detached from your surroundings. In the case above, you are just so absorbed in the movie that you are not paying attention to anything else but Casablanca. Still, you are detached, or dissociated from your environment, although not to a great extent. 

Ifound the exercise on the internet. attached is the list mentioned above.in order for a compound to be considered optically active it can't have any axis or plan of symmetry. the molecule  shouldn't also  be superimposable on its mirror image.with such considerations, the compounds that are optically active are: -third compound on the first image is optically active; -second and third compound from the second image are optically actives.