1、-Have you ______ been to the space station?-NO,I have ______ been there
2、-Havedone your homework ______?-Yes,I have.I have ______ done it.
3、I havebeen in China for two years _____.
4、My brother has _______ seen an interesting place_______.
10、His parents have ________ gone to paris,,so he is ai home alone.