题目

下列各组热化学方程式中，化学反应的△H前者大于后者的是  （       ）         ①C(s)＋O2(g)====CO2(g)；△H1    C(s)＋O2(g)====CO(g)；△H2 ②S(s)＋O2(g)====SO2(g)；△H3    S(g)＋O2(g)====SO2(g)；△H4 ③H2(g)＋O2(g)===H2O(l)；△H5   2H2(g)＋O2(g)====2H2O(l)；△H6 ④CaCO3(s)====CaO(s)＋CO2(g)；△H7   CaO(s)＋H2O(l)====Ca(OH)2(s)；△H8 A．①           B．④           C．②③            D．②③④23、Animals have the power to make themselves understood by man，especially when they are in serious danger and wish man to help them．And they often unite to help one another．1 was on a sheep farm in North America once when one of the sheep came crying to the tent（帐篷） late in the afternoon．She made the most painful cries．My friend，whom 1 was visiting，told me that something was wrong．     Together we followed the sheep back to where she had been eating grass on the farm．She Rushed（冲）forward and kept on looking back to see if we were coming．She finally led us to an old well （水井）and we heard the sad voice of her young baby that had fallen into the well．As the well had no water in it and was only six feet deep．We got a ladder and in a few minutes the baby went back to its mother. She seemed very, happy at the successful outcome（结果）of the accident．She had had come and told US her trouble and got help． （   ）1．In the stop the writer “I”was        A．the owner of a sheep farm        B．a visitor of a sheep farm        C．feeding sheep on a farm in North America     D．helping one of his friends to look after the sheep （   ）2．What did the sheep come to the tent for one day?        A．For help．      B．For food       C．For water    D．For its friend． （   ）3．How did the farmer know that something was wrong?       A．By talking to the mother sheep．              B．In a strange way．       C．By thinking about it together with Iris friend．   D．According to his experience． （   ）4．What happened to her baby?       A．There was no water for it．      B．There was not food for it．       C．It was hurt and lay in the well     D．It fell into the well and could not come out of it （   ）5．Which of the following statements is not true according to the passage?       A．Animals have the power to make themselves understood by man。       B．Animals understood man．       C．Animals often help one another especially in danger． D．Animals wish man to help them in serious danger．