1. In modern times some ______(青少年) have got into the habit of taking drugs.
2. As the child has never seen a ______(彩虹)before, he was very excited.
3. Don't be _______ (失望的) when you fail for the first time.
4. Instead of _______ (吸烟), do something else.
5.The eruption of a volcano is an ______ (绝对地；完全地) fantastic sight.