1 . 用方框中单词的正确形式完成句子。

extinct       definite       equip       usual       energy

1. Working out regularly, he is always ________.
2. Never go climbing without the proper ________.
3. The boy’s ________ behaviour puzzled the doctor.
4. Many endangered species are now facing the danger of ________.
5. It was an amazing atmosphere — ________ the best one I’ve ever experienced.