不属于CT重建方法的有() A.反投影法 B.迭代法 C.滤波反投影法 D.傅立叶重

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问题:

不属于CT重建方法的有()

A.反投影法

B.迭代法

C.滤波反投影法

D.傅立叶重建法

E.扫场法

考点:放射医学技术(师)CT成像理论CT成像理论题库
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下属部门只接受一个上级的指令,各级主管负责人对所属单位的一切问题负责,这是哪一种组织结构类型()

A.职能制

B.网络型结构

C.直线职能制

D.直线制

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GUATEMALA CITY (Reuters) – A fish that lives in mangrove swamps(红树沼泽) across the Americas can live out of water for months at a time, similar to how animals adapted(适应) to land millions of years ago, a new study shows.

The Magrove Rivulus, a type of small killifish, lives in small pools of water in a certain type of empty nut or even old beer cans in the mangrove swamps of Belize, the United States and Brazil. When their living place dries up, they live on the land in logs(圆木), said Scott Taylor, a researcher at the Brevard Endangered Lands Program in Florida.

The fish, whose scientific name is Rivulus marmoratus, can grow as large as three inches. They group together in logs and breathe air through their skin until they can find water again.

The new scientific discovery came after a trip to Belize.

“We kicked over a log and the fish just came crowding out,” Taylor told Reuters in neighboring Guatgemala by telephone. He said he will make his study on the fish known to the public in an American magazine early next year.

In lab tests, Taylor said he found the fish can live up to 66 days out of water without eating.

Some other fish can live out of water for a short period of time. The walking catfish found in Southeast Asia can stay on land for hours at time, while lungfish found in Australia, Africa and South America can live out of water, but only in an inactive state. But no other known fish can be out of water as long as the Mangrove Rivulus and remain active, according to Patricia Wright, a biologist at Canada’s University of Guelph.

Further studies of the fish may tell how animals changed over time.

“These animals live in conditions similar to those that existed millions of years ago, when animals began making the transition(过渡) from water onto land,” Wright said.

1. The Mangrove Rivulus is a type of fish that _______.

A. likes eating nuts

B. prefers living in dry places

C. is the longest living fish on earth

D. can stay alive for two months out of water

2. Who will write up a report on Mangrove Rivulus?

A. Patricia Wright.

B. Scott Taylor.

C. Scientists from Belize.

D. Researchers in Guatemala.

3. According to the text, lungfish can ________.

A. breathe through its skin

B. move freely on dry land

C. remain alive out of water

D. be as active on land as in water

4. What can we say about the discovery of Mangrove Rivulus?

A. It was made quite by accident.

B. It was helped by Patricia Wright.

C. It was based on a lab test of sea life.

D. It was supported by an American magazine.

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预混合饲料

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张某,男,12岁。夏季饮冷后出现腹痛泄泻,便质清稀,水谷相混,肠鸣腹胀,得温痛减,口不渴,舌淡,苔白滑,脉迟。治疗在主要穴位的基础上加用()。

A.梁门、中脘

B.支沟、下脘

C.内庭、曲池

D.天枢、下脘

E.神阙、关元

题型:单项选择题

YC6LN-50系列气体发动机的低压电磁阀由线圈驱动阀芯,由ECU控制其开合,停机状态下处于()状态。

A、常开

B、常闭

C、常开或常闭

D、半开半闭

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