单词拼写（共5小题，每小题1分，满分5分）
根据下列句子及所给的单词的首字母写出所缺单词。在填写答卷时，要求写出完整单词。（每空只写一词）
I f_________ to close the window when I left home.
The library l_________ in the corner of the street.
If you want to know what the word m_________，look it up in the dictionary.
Oxygen is a kind of important g_________ for people.
If you want to plant a trees, first you should d_________ a hole.