1.   And yet, in these past hectic weeks, Yeltsin has surprised his harshest detractors by proving that he can still make decisions, and even impromptu appearances.

2.   Big names tend to sign on late or make impromptu appearances, giving festival organizers headaches while delighting surprised festival-goers.

3.   Diplomats and officials have been worried that Mrs. Mandela might make an impromptu appearance.

4.   In fact, their impromptu appearances on stage were one of the things Stewart and Jacobsen looked forward to every year in Houston.

5.   The season ended with the fans interrupting their fistfights in the stands and their impromptu appearances on the field to boo an injured Joe Montana.

6.   On leaving the community center, Bush made an impromptu appearance at an adjacent hockey rink where four teams of young children were practicing.