题目

下列各组离子因为发生氧化还原反应而不能大量共存的是( ) A．Na＋ Fe3＋ Cl－ SCN－ B．Ba2＋ NO K＋ OH－ C．Fe2＋ Cl－ SO OH－ D．Fe3＋ Na＋ I－Cl－ 答案：解析：选D A中Fe3＋与SCN－结合生成络合物Fe(SCN)3，不符合题意；B中离子可以大量共存，不符合题意；C中Fe2＋不能与OH－共存，是因为能生成Fe(OH)2沉淀，不符合题意；D中Fe3＋不能与I－共存，Fe3＋能将I－氧化，符合题意。 II. 完形填空（共15题，每小题2分，共30分） My best friend is Cocoa, and I live in a senior-citizen apartment. Cocoa is a ten-year-old dog and I am a sixty-nine-year-old lady, so you can see we both qualify as   11  citizens. He is a   12  companion. He does many amusing things that make me  13  , and when that happens, he is so delighted  14  he just keeps it up. But one afternoon, Cocoa started acting strangely. I was sitting on the floor playing with him,  15  he started pawing and smelling at the right side of my  16  . He had never done anything like this ever before, and I told him, “No.” To Cocoa, one “no” is usually  17 , but not that day. He stopped briefly, and then  18   ran toward me, throwing his entire weight at the right side of my chest. He crashed into me and I cried in   19  , falling down to the floor. Soon after this, I felt a lump (肿块). I went to my doctors, and after X-rays  20   and lab work were done, they told me I had cancer. When cancer starts, a  21   of calcium (钙) builds. Then the lump or cancer attaches itself to this wall. When Cocoa jumped on me, the force of the impact broke the lump away from the wall. This made it possible for me to  22   the lump. I had a complete mastectomy (乳房切除术) and the cancer has not   23  to any other part of my body. The doctors told me if the cancer had gone undetected even six more months, it would have been too  24  . Was Cocoa  25   of just what he was doing? I’ll never really know. What I do know is that Cocoa not only shares his life with me, he has also made sure that I will be around to share my life with him! 11    A.    good       B.    standard  C.    senior      D.    great 12    A.    wonderful       B.    tiring      C.    hungry    D.    bad 13    A.    leave       B.    cry   C.    laugh      D.    jump 14    A.    as    B.    when      C.    and  D.    that 15    A.    when       B.    then C.    though    D.    as 16    A.    chest       B.    body       C.    shoulder  D.    arm 17    A.    right       B.    good       C.    enough    D.    unexpected 18    A.    hurriedly B.    rudely     C.    slowly     D.    suddenly 19    A.    pain B.    surprise   C.    trouble    D.    danger 20    A.    experiments    B.    researches       C.    tests       D.    papers 21    A.    wall B.    cancer     C.    body       D.    number 22    A.    watch      B.    have C.    get   D.    notice 23    A.    ran   B.    kept C.    entered    D.    spread 24    A.    common  B.    late  C.    much      D.    early 25    A.    ashamed  B.    aware      C.    afraid      D.    tired