11, Telephones are always invented by my brother.
12, The chores are often done by Lan on Sundays.
13, The meal is cooked by themselves.
14, Fish and vegetables are usually bought for her mother by Tan.
15, The saucepan and frying pan are not used by us.
16, Is Aunt Hoa called by you every night?
17, Is the rug put between the armchair and the couch by your mother?
18, Children are not let play in the kitchen by the mother.
19, Matches are not played with by children.
20, The garbage is always emptied by my younger sister in the early morning.