阅读下列短文，根据短文内容填空。在未给提示词的空白处仅填写1个适当的单词，在给出提示词的空白处用括号内所给词的正确形式填空。

After a lot of preparation, Joseph Lockwood and Philippa Amos were finally ready to start their journey into the Amazon rainforest. They were feeling (cheer) as they sailed down the great river. Eventually, they got out of the boat and walked into the darkness of the jungle. Neither of them had ever been in such an extreme situation before, using just a compass (指南针) to find the area where the kind of frog they wanted to study  (live). Suddenly, Joseph, who was holding the compass, tripped and lost it in a river. The situation seemed hopeless—how would they find the frogs now? But just  they started to feel really sad and worried that their journey  (be) a failure, they saw the frogs they had come to look for.