Grammar - 1. Observation (5ms) Find out the following sentences which belong to Passive Voice.　

Yesterday I listened to music at home. A sound of piano is heard in the living room. Alexander Graham Bell invented the telephone in 1876. An article was written by him. They know that he is an expert. In Pakistan rice will be grown in many parts of the country. The new hybrid rice has been developed by the Yuan Longping High-tech Agricultural Company of China.

present simple1

past simple

refers to the future

present prefect