问题 选择题

小翔同学对所学部分化学知识归纳如下,其中有错误的一组是  

A.实验现象B.安全常识
红磷在空气中燃烧——大量白雾

稀盐酸中滴加石蕊——溶液变红

进入陌生溶洞前——先做灯火实验

冬天用煤炉取暖——保证室内通风

C.化学与健康D.化学与生活
缺铁——易引起贫血

缺碘——易患甲状腺肿大

区别老陈醋与酱油——闻气味

区分硬水与软水——用肥皂水

 

答案

答案:A

题目分析:对于化学实验现象的描述要注意准确性,A、红磷在空气中燃烧是产生大量的白烟,一定要注意“烟”和“雾”的区别,“烟”是固体小颗粒,而“雾”是液体小液滴,因为白磷燃烧生成的是P2O5固体,所以是白烟,而不是白雾,酸溶液能使紫色石蕊试液变红,对的; B、由于二氧化碳的密度比空气大,且不能供给呼吸,一旦CO2的浓度过大,对人的生命会造成危险,陌生溶洞,由于与外面空气不对流,导致里面就会可能有大量的CO2聚集,如果这个时候贸然进去会有危险,所以应该先做灯火实验,煤的主要成分是碳,当它在氧气充足的时候燃烧生成二氧化碳,但氧气不足的时候,就会生成一氧化碳,而一氧化碳有剧毒,所以冬天用煤炉取暖——保证室内通风;C、化学微量元素与人体身健康息息相关,像缺铁——易引起贫血,缺碘——易患甲状腺肿大,缺锌—食欲不振,生长迟缓,缺硒—表皮角质化和癌症,缺氟—患龋齿;D、根据物质的性质可以区分物质,醋有刺激性气味,而酱油无气味,所以可以根据闻气味进行区分,硬水加入肥皂水振荡,泡末少,浮渣多,而软水中加入肥皂水振荡,泡末丰富,浮渣少,故选A

完形填空

第二节 完型填空(共20小题,每小题1分,满分20分)

A friend once told me a beautiful story of how ordinary people found a simple way to help others. My friend was 36 the beautiful view on the top of Casper Mountain, a 37 place for visitors to overlook (俯视) Casper, Wyoming. Even in the summer it was 38 on top of the mountain, and on this day he 39 a young woman who clearly had no coat. She 40 as she wrapped (用……缠绕) her arms around herself.

Then he saw an older man 41 up to the young woman, take off his sweater and place it on her 42 . The man said, “Here, keep the sweater. The 43 is even better when you’re warm.” She smiled her 44 and wrapped the warm sweater 45 her shoulders as the man went away.

Before the woman left, she found a middle-aged woman who was also 46 cold and she handed her the sweater. “47 it,” she said. “The view is even better when you’re warm.”

My friend was 48 in that, so he kept his eyes on the sweater. He noticed that before the current (现在的) 49 of the sweater left, she came near to a trembling (颤抖的) man, 50 it to him and said, “Here ... keep the sweater. The view is 51 better when you’re warm.”

“That happened a couple of years ago,” my friend said. “And as far as I know, that 52 is still on top of Casper Mountain, going from one person to another.”

Ordinary people can find a way to 53 others. Great opportunities to help others seldom come, but small ones 54 us daily. Like somebody else likes to say: Nobody can help everybody, 55 everybody can help somebody!

36. A. getting      B. enjoying       C. taking              D. making

37. A. dirty      B. terrible         C. favorite        D. cold

38. A. hot             B. sunny          C. cool                    D. warm

39. A. liked           B. knew           C. touched        D. noticed

40. A. laughed           B. cried          C. feared          D. shook

41. A. walk           B. rush             C. jump             D. swim

42. A. shoulders     B. hands          C. arms                D. legs

43. A. health      B. picture         C. result               D. view

44. A. thanks         B. apologies      C. dissatisfaction   D. greetings

45. A. on           B. by               C. with                    D. around

46. A. silently     B. clearly         C. especially       D. finally

47. A. Throw            B. Buy          C. Keep               D. Mend

48. A. surprised     B. interested            C. shocked            D. frightened

49. A. helper      B. giver          C. owner             D. seller

50. A. gave           B. sold          C. showed         D. bought

51. A. quite        B. never               C. ever              D. much

52. A. man            B. woman        C. mountain       D. sweater

53. A. compete           B. help             C. fight                    D. forgive

54. A. catch           B. miss             C. surround (包围)  D. welcome

55. A. if              B. unless           C. so                    D. But

选择题