--Do you often hear Tom ____in the next room?

--No, but he is often heard____ the guitar in the garden outside.

A．sing; to play          B．to sing; play       C．sing; play                D．singing; play

----Do you often hear Tom _____________ in the next room ?

----No, but he is often heard ______________ the guitar in the garden outside.

A. sing; to play　 B. to sings; play　　 C. sing; play　 D. singing; play