根据句意和提示， 在横线上填写适当的单词， 使句子完整、正确．
﹣Come on，Sandy．Everybody will be lucky or （成功的） sometime in their life．
﹣Thanks，I'll try again．
这个暑假你打算做什么？
Spud Web's success proves that one can hardly realize his dream hard work．
The Chens have moved into a new flat，leaving their old house （having nobody inside）．
We don't （be not sure if something is true）the great achievements China has made in the past 40 years．
How calm and brave the command （飞行员）was to fly the plane back safely in such a dangerous situation！