题目

将下列各组物质溶于水，所得溶液中只有一种溶质的是( ) A．NaCl和Na  B．Na2O和Na2O2 C．Na2O2和Na2CO3  D．NaCl和NaOH 答案：【解析】 A项得到的溶质分别是NaCl和NaOH；B项得到的溶质都是NaOH；C项得到的溶质分别是NaOH和Na2CO3；D项得到的溶质分别是NaCl和NaOH。 【答案】 B完形填空（共20小题；每小题1分，满分20分）   阅读下面短文，掌握其大意，然后从各题所给的四个选项（A、B、C、D）中，选出最佳选项，并在答题卡上将该项涂黑。 Positive Thought—A Strong Tool of Success Once upon a time there was a bunch of tiny frogs that arranged a running competition. The  36  was to reach the top of a very high tower. A big crowd had  37  around the tower to see the race and  38  on the competitors. The race began. Honestly, no one in the crowd really  39  that the tiny frogs would reach the top of the tower. You heard  40  such as, “They will  41  make it to the top. Or: Not a chance that they will  42  . The tower is too high!” The tiny frogs began falling,  43  , except for those, who in fresh tempo (速度) were climbing higher and higher. The crowd  44  to yell (大叫), “It’s too difficult!!! No one will make  45  !” More tiny frogs got tired and gave up, but one continued higher and higher and higher. This one wouldn’t give up! At the end,  46  else had given up  47  the tower, except for one tiny frog. After a big  48  , he was the only one who reached the top! Then all the other tiny frogs  49  wanted to know how this frog  50  to do it. A competitor asked the tiny frog  51  he had found the  52  to succeed and reach the goal. It turned out…that the winner was  53  !!!! Never listen to other people’s tendencies to be  54  or pessimistic (悲观的) because they take your most  55 dreams and wishes away from you—the ones you have in your heart! You should always be positive and above all be deaf when people tell you that you cannot fulfill your dreams! 36. A. dream                                B. end                                   C. result                     D. goal 37. A. prepared                B. gathered             C. started         D. hidden 38. A. cheer                   B. depend              C. call              D. turn 39. A. doubted                B. hoped               C. believed         D. predicted 40. A. statements                       B. lines                  C. orders        D congratulations 41. A. finally                     B. sometimes           C. always                             D. never 42. A. fail                      B. succeed              C. fight                     D. follow 43. A. one by one                B. hand in hand            C. year after year            D. up and down 44. A. stopped                 B. wished               C. continued                D. forgot 45. A. that                    B. them                C. one                    D. it 46. A. nobody                 B. everyone              C. something              D. a few 47. A. climbing                  B. building                C. painting                D. examining 48. A. rest                    B. decision                C. effort                  D. difference 49. A. politely                    B. carefully                C. naturally                D. seriously 50. A. pretended               B. tried                  C. happened                        D. managed 51. A. why                   B. how                C. when                     D. whether 52. A. strength                          B. power               C. secret                   D. bravery 53. A. blind                    B. disabled               C. dead                    D. deaf 54. A. positive                   B. negative               C. common                 D. active 55. A. interesting                 B. dangerous            C. wonderful               D. frightening