it's right __us__speak politely to the old.A of;to B for;to

it's right __us__speak politely to the old.A of;to B for;to The old should （）（speak）to politely.It is implite of you to it's a good b——to make room for the old in the bus It's selfish of ____ not to make a seat for the old man in t It's very right----you to help the old. You should speak to the old politely. It's easy ( )the work.A.to doing B.of youto do C.for you to -It's very kind of you to help me.-( ).A.All right B.It's a Maybe it's the right time for me to give Old people must A be spoken to politely B speak to polite C 17.Old people must_____.A.be spoken to politely B.speak to p It's not right to _____ (be rude to )the old.