6. I don't recall........him at the conference. A. having seen B. to have seen C. having been seen D. to have been seen 7.......... in dark colors, the room needed some bright lights. A. Having painted B. To have paintedC. Having been painted D. To have been painted 8. The stockbroker denied .........of the secret business deal. A. having informed B. to have informedC. having been informed D. to have been informed 9. They now regret ........ their son by providing too many material possessions. A. having spoiled B. to have spoiledC. having been spoiled D. to have been spoiled 10....... to the party, we could hardly refuse to go. A. Having invited B. To have invitedC. Having been invited D. To have been invited # Giải thích giúp nhé