The missing boys were last seen _____ near the river.

　 A. playing 　 B. to be playing  C. play 　 D. to play

The missing boys were last seen _____ near the river.

　 A. playing 　 B. to be playing C. play 　 D. to play

The missing boys were last seen____ near the river.

A.     playing  B. to be playing  C. play  D. to play

The missing boys were last seen ___ near the river.

A. playing  B. to be playing  C.play   D. to play

The missing boys were last seen _______ near the river.

A. to play                                                                   B. to be playing

C. play                                                                        D. Playing