问题 选择题

航天探测发现:金星是一个被浓密大气层包围的固体球,大气层的成分之一是C2O3实验证明其化学性质与CO相似。下列关于C2O3的说法不正确的是(     )

A.C2O3中碳的化合价为+3

B.C2O3,能使紫色石蕊溶液变红

C.在一定条件下C2O3能还原氧化铁

D.C2O3充分燃烧的产物是CO2

答案

答案:B

A、氧的化合价为-2,正价与负价和为零推出碳为+3价,A正确

B、根据CO不能使澄清石灰水变浑浊,三氧化二碳化学性质与一氧化碳相似,可判断C2O3不能使紫色石蕊溶液变红;B不正确

C、三氧化二碳化学性质与一氧化碳相似,一氧化碳可以还原金属氧化物,C正确

D、三氧化二碳化学性质与一氧化碳相似,一氧化碳能燃烧生成二氧化碳,D正确

故选:B

完形填空

第二节:完形填空(共20小题;每小题1.5分,满分30分)

阅读下面短文,掌握其大意,然后从16-35各题所给的A、B、C、D四个选项中选出最佳选项。

My earliest memory of dad is grabbing his hand while we walked together. As I   16   older, I remember my father and I listening to basketball games on the radio. I always fell asleep   17   the game was over. When I woke up in the morning the score sheet with the   18   score on it would be lying   19   me. I’ll always remember that.

On cold mornings my father would bring his bread truck by the house. I used to ride on the floor of that bread truck  20   he delivered the bread to the stores. The   21   and the warmth from the bread made my mouth water and kept me warm. I’ll always remember that.

My father would   22   all my games. One night before an important game my father told me   23   that he wouldn’t be able to watch the game because he had to deliver the bread and it was a three-hour   24   from his route(路线). The next day as the game time approached I thought about my dad. I happened to look across the field and   25   saw his bread truck pulling into the stadium. He managed to   26   the game. I’ll always remember that.

Years later I had become a teacher. I’ll never forget the voice on the phone early one morning telling me dad had just been   27   in a traffic accident. I could hear my heart   28   in my ears. I   29   the phone and went back to my bedroom. After that nothing really   30   to me. I still taught in school   31   I couldn’t focus on my teaching. One day I was on the playground

32   a little boy walked up to me and grabbed my hand. His hand held mine the same way I used to hold my father’s by the last two   33  . At that moment I found my   34   in life again. You see even though my father was gone, he left something with me. He left me his smile, compassion and touch. My purpose was to use those   35   as he did. From that day On I started. I’ll always remember that!

16.A.seemed            B.grew                      C.turned                    D.changed

17.A.when               B.although                 C.because                   D.before

18.A.fresh               B.final                       C.official                   D.opposite

19.A.across from      B.in place of                     C.next to                    D.ahead of

20.A.as                   B.so                          C.until                       D.unless

21.A.smell               B.color                      C.taste                       D.shape

22.A.react               B.confirm                  C.serve                      D.attend

23.A.exactly            B.sadly                      C.slowly                    D.simply

24.A.drive               B.walk                       C.length                     D.ride

25.A.immediately     B.hopefully                C.surprisingly             D.unusually

26.A.make               B.keep                       C.take                        D.win

27.A.killed                     B.injured                   C.trapped                   D.saved

28.A.strike                     B.knock                     C.beat                        D.hit

29.A.held up            B.held back                C.hung on                  D.hung up

30.A.cared               B.mattered                 C.troubled                  D.meant

31.A.if                    B.once                       C.and                        D.but

32.A.while                     B.after                       C.when                      D.before

33.A.shoulders         B.fingers                    C.arms                       D.legs

34.A.purpose           B.pleasure                  C.position                  D.progress

35.A.lessons            B.prizes                     C.gifts                       D.subjects

单项选择题