患者女,74岁,上下颌牙列缺失,要求重新行全口义齿修复,查见上颌弓小,下颌弓大,上颌

题型:单项选择题

问题:

患者女,74岁,上下颌牙列缺失,要求重新行全口义齿修复,查见上颌弓小,下颌弓大,上颌唇颊侧骨组织吸收明显,下颌牙槽嵴较丰满,原全口义齿按正常排牙,上颌固位差,若重做全口义齿应该了解。

下列哪一项不是颌位关系异常的临床表现

A.上颌前突

B.上下牙槽嵴低平

C.下颌前突

D.颌间距离小

E.下牙弓宽于上牙弓

考点:口腔医学技术(主管技师)口腔技师相关专业知识中级口腔医学主管技师相关专业知识
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通过发酵罐发酵可大规模生产谷氨酸,生产中常用的菌种是好氧的谷氨酸棒状杆菌。下面有关谷氨酸发酵过程的叙述,正确的是[ ]

A.溶氧充足时,发酵液中有乳酸的积累

B.发酵液中碳源和氮源比例的变化不影响谷氨酸的产量

C.菌体中谷氨酸的排出,有利于谷氨酸的合成和产量的提高

D.发酵液pH值呈碱性时,有利于谷氨酸棒状杆菌生成乙酰谷氨酰胺

题型:单项选择题

腮腺的超声检查方法,最适宜的是()

A.采用7~10MHz频率探头,多切面进行检查

B.理发后,多切面进行检查

C.空腹进行多切面检查

D.主要观察腮腺的血管及神经分布

E.进行纵切面检查

题型:单项选择题

A house of cards? Sounds unbelievable, doesn’t it? Not if the architect is 31-year-old Bryan Berg. He’s made a career out of building fantastic card houses, stadiums, capitols, castles — and the world’s tallest card tower. How does he do it?

Bryan’s structures are amazing because they are made entirely of perfectly balanced, freestanding playing cards. He never uses glue, tape, or anything else to hold the cards together. Nor does he fold the cards. He’s discovered another way to make a strong house of cards, using a trick from nature.

To make plants strong, nature builds them with cells that have tough walls. Rows and rows of these cells form a grid(格子) that helps leaves and stems keep their shape. Bees use the same kind of repeating pattern to create strong honeycombs, where they live and store honey. Bryan designs similar grids, using cards to create a repeating pattern of cells.

He begins with a single cell made by balancing four cards against one another to form a box. Then he repeats the cell over and over, expanding outward to form the grid, which makes a good foundation for a strong card structure. The larger the grid, the more weight it can carry. Sometimes Bryan uses several cards, instead of just one, to construct the cell walls, making the grid even stronger. The trick, he tells kids when he speaks in classrooms, is to place your cards as tightly together as possible when laying out your grid, making sure the cards are not leaning at all.

After building this solid base, Bryan lays cards across the top to make the floor for the next “story” of the building. He may add towers, columns, steeples, or domes. Using the principle of repeating cells, Bryan builds structures of amazing strength.

In the Cards

Not surprisingly, Bryan has always been interested in building things. Growing up on a “big, old farm” in rural Iowa, he had plenty of room to play. “We were in the middle of nowhere,” Bryan remembers, “with lots of space to do whatever we wanted. I was always making something, using things like sticks or bales of hay.”

Bryan’s grandfather taught him how to stack cards. Bryan’s two interests — building and card stacking — soon combined. But stacking in his family’s farmhouse was challenging. “Our old house had wood floors that weren’t all level,” he reports. “And they weren’t very firm. When people walked around, it was like ‘earthquake action.’ It was a challenge to build something that wouldn’t fall down immediately.”

Bryan constructed tower after tower; he went through a lot of trial and error before he built anything taller than himself. When he placed a few decks of cards on top of his grid, he discovered how strong it was. Bryan’s towers began to grow taller.

How Tall Is Too Tall?

Bryan’s first Guinness World Record for the world’s tallest card tower came in the spring of 1992, when he was in high school. Learning that the world record was 12 feet 10 inches, Bryan built a slim tower that topped out at 14 feet 6 inches. Done as a project for his geometry class, it took him 40 hours and 208 decks of cards. Since then he’s gone on to win world records for even taller buildings. His latest winner measured 25 feet 3.5 inches and used about 2,400 decks of cards. The building, which tapered to a high, narrow point, had 131 stories.

Why don’t these towers fall down? The key is in a good solid base, a repeating pattern of stories, and a tapering top. Bryan likes to point out how card buildings resemble real ones. They are built cell by cell, story by story. The separate parts make one strong whole. The heavier the building, the stronger and more stable it is. But the weight can’t all be at the top.

After spending so much time building something so cool, Bryan admits it’s sometimes painful to see his structures destroyed. But he compares his work to the building of a sandcastle or an ice sculpture.

“They wouldn’t be as special if they were permanent,” he points out. “My buildings are like snowdrifts, or clouds in the sky. They can’t last forever.

小题1:According to the article, which natural structure is a model for Bryan’s card structures?

A.A sand dune.

B.A honeycomb.

C.A snowdrift.

D.A thundercloud.小题2:What was Bryan’s first world record?

A.The tallest card tower.

B.The widest card dome.

C.The heaviest card house.

D.The sturdiest card structure.小题3:Bryan’s hobby is the result of combining which two boyhood interests?

A.Plant cells and honeycombs.

B.World records and geometry.

C.Building things and stacking cards.

D.Playing cards and designing houses.小题4:Why was it a challenge for Bryan to build card structures in his family’s farmhouse?

A.The floors of the house were uneven.

B.The ceilings in the house were too low.

C.The floors of the house were slippery.

D.The windows in the house were windy.小题5:In the underlined sentence, the word “tapered” means the top of the building was_________.

A.older

B.shinier

C.stronger

D.thinner

题型:单项选择题

公安民警职务设置为( )三个序列。

A.领导职务

B.执行职务

C.专业技术职务

D.综合职务

题型:单项选择题

纤维的断裂伸长偏低时,可采取的调整方法是()。

A、提高牵伸倍数

B、降低牵伸倍数

C、增加集束桶数

D、减少集束桶数

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