根据所给音标及释义写出单词。
1.
_____ [
] a small piece of paper that one sticks on an envelope (信封)
2.
_____ [
] keep something for a later time
3.
_____ [
] especially (特别的)
4.
_____ [
] the most important city of a country or state
5.
_____ [
] a person from another country
6.
_____ [
] sure; not doubtful (可疑的)