红磷P(s)和Cl2(g)发生反应生成PCl3(g)和PCl5(g)。反应过程和能量关系如图所示（图中的△H表示生成1mol产物的数据）。
根据上图回答下列问题：
（1）P和Cl2反应生成PCl3的热化学方程式是__________ ；
（2）P和Cl2分两步反应生成1 mol PCl5的△H 3= _____________；
（3）PCl5与足量水充分反应，最终生成两种酸，其化学方程式是____________ 。
（1） Cl2(g)+ P(s)== PCl3(g) △H =-306kJ/mol ；
（2）-399kJ/mol；
（3）PCl5+4H2O==H3PO4+5HCl
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Mozart and an Old Performer One day Mozart (莫扎特)saw an old blind street performer (卖艺人) playing the violin in the street corner __1__ a hat in front of him. He found out the old man was __2__ one of his compositions (作品).The old man played for __3__ , but still nobody put any money into his hat. Mozart asked the old man, "Do you often play compositions by Mozart?" "Yes, __4__ ," answered the old man. "Now, everybody knows Mozart and likes his music." "Do you __5__ a living by playing the violin?" The old man said he __6__ Mozart took over the violin from the old man and began to play. He played so well __7__ all the passer-by stopped to listen the wonderful music and soon the old man felt very __8__ that the man could play so well. He asked Mozart, "Who are you, sir?" "Your colleague (同行) , a poor __9__ like you." Then Mozart gave the __10_ back to the old man and went away. | |||
( )1. A．on | B．by | C．with | D．to |