1) Acted as host 2) Acted as toastmaster 3) Acted the host 4) Controlled the mike 5) Did the honors 6) Emulated Alex Trebek 7) Filled in for Leno 8) Headed the roast 9) Hosted 10) Hosted a roast 11) Hosted or roasted 12) Hosted the show 13) Hosted, toasted or roasted 14) Introduced acts 15) Introduced performers 1) Hosted 2) Led