最容易侵犯神经的唾液腺肿瘤是() A.腺泡细胞癌 B.黏液表皮样癌 C.腺样囊性癌

题型:单项选择题

问题:

最容易侵犯神经的唾液腺肿瘤是()

A.腺泡细胞癌

B.黏液表皮样癌

C.腺样囊性癌

D.上皮肌上皮癌

E.导管癌

考点:口腔五官科主治医师口腔内科基础知识口腔内科学基础知识
题型:单项选择题

下列胸部疾患X线摄影位置,正确的是()

A.肺下积液-后前位

B.肺癌-常规正侧位加体层摄影

C.慢性支气管炎-后前位深吸气与深呼气位对照

D.包裹性积液-切线位

E.少量胸腔积液-侧卧水平正位或斜位

题型:单项选择题

维生素C是一种水溶性维生素(其水溶液呈酸性),它的化学式是C6H8O6,人体缺乏这样的维生素能得坏血症,所以维生素C又称抗坏血酸。在新鲜的水果、蔬菜、乳制品中都富含维生素C,例如新鲜橙汁中维生素C的含量在500mg/L左右。某校课外活动小组测定了某牌子的软包装橙汁中维生素C的含量,下面是测定实验分析报告。

(请填写有关空白)

(一) 测定目的:测定××牌软包装橙汁中维生素C的含量。

(二) 测定原理:C6H8O6+I2→C6H6O6+2H++2I-

(三) 实验用品及试剂

(1)仪器和用品(自选,略)

(2)试剂:指示剂______________(填名称),浓度为7.50×10-3 mol·L-1的I2标准溶液、蒸馏水等。

(四) 实验过程

(1) 洗涤仪器,检查滴定管是否漏液,润洗后装好标准碘溶液待用。

(2) 用_________(填仪器名称)向锥形瓶中移入20.00mL待测橙汁,滴入2滴指示剂。

(3) 用左手控制滴定管的_________(填部位),右手摇动锥形瓶,眼睛注视__________________,直到滴定终点。滴定至终点时的现象是___________________。

(五) 数据记录与处理(请在下面设计并画出数据记录和数据处理的表格,不必填数据)。 若经数据处理,滴定中消耗标准碘溶液的体积是15.00mL,则此橙汁中维生素C的含量是____________mg/L。

(六) 问题讨论:

(1)滴定时能否剧烈摇动锥形瓶?为什么?______________________________

(2)从分析数据看,此软包装橙汁是否是纯天然橙汁?_______(填“是”或“不是”或“可能是”)。

制造商最可能采取的做法是__________(填编号):

A.加水稀释天然橙汁 B.橙汁已被浓缩 C.将维生素C作为添加剂

题型:单项选择题

25K型客车基础制动装置采用单元盘形制动装置。

题型:单项选择题

对于申请答辩的硕士论文,应在预定答辩时间()前,以学院为单位,提交电子版到校学位办公室。校学位办公室将采用《学位论文学术不端行为检测系统》对论文进行抽查审核。

A.一周前

B.两周前

C.三周前

题型:单项选择题

Children start out as natural scientists, eager to look into the world around them. Helping them enjoy science can be easy; there’s no need for a lot of scientific terms or expensive lab equipment. You only have to share your children’s curiosity. Firstly, listen to their questions. I once visited a classroom of seven-year-olds to talk about science as a job. The children asked me "textbook questions" about schooling, salary and whether I liked my job. When I finished answering, we sat facing one another in silence. Finally I said, "Now that we’re finished with your lists, do you have questions of your own about science"

According to the passage, children are natural scientists, and to raise their interest, the most important thing for adults to do is ______.
A. to let them see the world around
B. to share the children’s curiosity
C. to explain difficult phrases about science
D. to supply the children with lab equipment

After a long pause, a boy raised his hand, "Have you ever seen a grasshopper eat When I try eating leaves like that, I get a stomachache. Why"
This began a set of questions that lasted nearly two hours.
Secondly, give them time to think. Studies over the past 30 years have shown that, after asking a question, adults typically wait only one second or less for an answer, no time for a child to think. When adults increase their "wait time" to three seconds or more, children give more logical, complete and creative answers.
Thirdly, watch your language. Once you have a child involved in a science discussion, don’t jump in with "That’s right" or "Very good". These words work well when it comes to encouraging good behavior. But in talking about science, quick praise can signal that discussion is over. Instead, keep things going by saying "That’s interesting" or "I’d never thought of it that way before", or coming up with more questions or ideas.
Never push a child to "Think". It doesn’t make sense, children are always thinking, without your telling them to. What’s more, this can turn a conversation into a performance. The child will try to find the answer you want, in as few words as possible, so that he will be a smaller target for your disagreement.
Lastly, show; don’t just tell. Real-life impressions of nature are far more impressive than any lesson children can learn from a book or a television program. Let children look at their fingertips through a magnifying glass, and they’ll understand why you want them to wash before dinner. Rather than saying that water evaporates, set a pot of water to boil and let them watch the water level drop.

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