题目内容：

单词拼写。根据英文首字母和所给汉语提示写出短文中所缺单词的正确形式。

   An invention may be a new 1.p_____ or a new way of doing things. 2.____(发明) come about in many ways. Most of the time, inventions 3. h____ because someone works to 4.(解决）______ a 5. p____ .