单项选择题
A．Books. B．newspapers. C．TV and radios. D．A,B,C and others.
A．understand the world and other people better B．teach each other to speak, write, read and draw C．know what other people are thinking about D．learn what's happening in the world more quickly
A．to tell the children not to throw stones at the notice B．to warn the boys not to throw stones C．to attract the boys to throw stones at the notice D．to warn them whoever threw stones would be punished