Ⅱ型柴胡皂苷具有()A.△齐墩果烷结构 B.13β、28-环氧醚键结构 C.同环双烯

题型:单项选择题

问题:

Ⅱ型柴胡皂苷具有()

A.△齐墩果烷结构

B.13β、28-环氧醚键结构

C.同环双烯结构

D.异环双烯结构

E.齐墩果酸结构

考点:执业中药师中药化学成分与药效物质基础中药化学成分与药效物质基础题库
题型:单项选择题

The Mayan(玛雅的)Indians lived in Mexico for thousands of years before the Spanish arrived in the 1500s. The Mayan achievements were many. They had farms, beautiful palaces, and cities with many buildings. The Mayan people knew a lot about nature and the world around them. This knowledge helped them to live a better life than most people of that time, because they could use it to make their lives more comfortable and rewarding(值得的). Knowledge about tools and farming, for example, made their work easier and more productive.

The Maya believed in many gods, including rain gods, sun gods, and corn gods. The people built large temples to honor the Mayan gods. Skillful workers built cities around these temples. It was difficult for them to build these cities, because they had no horses to carry the heavy stone they used to build with. Workers had to carry all of the building materials themselves. Today, many of these ancient Mayan cities and temples are still standing.

Although the cities that the Maya built were beautiful, and the people worked hard to build them, very few of the people lived in them. Usually, only the priests(牧师)lived in the cities.

The other people lived in small villages in the forests. Their houses were much simpler than the elaborate buildings in the cities. They lived in small huts(小屋)with no windows. The walls were made of poles covered with dried mud, and the roof was made of grass or leaves. Most Maya lived a simple life close to nature.

The Mayan priests studied the Sun, the Moon, stars, and planets. They made a calendar from what they learned. The year was divided into 18 months of 20 days each with five days left over. The Mayan calendar was far more exact than the European calendars of the time.

Around the year 800, the Maya left their villages and beautiful cities, never to return. No one knows why this happened. They may have died from some disease. They may have left because the soil could no longer grow crops. Archaeologists(考古学家)are still trying to find the lost secrets of the Maya.

小题1:What does the underlined word “elaborate’’ mean?

A.easily built

B.carefully made

C.slowly fixed

D.quickly designed小题2:From the passage we can infer(推理)that   .

A.most Maya lived in beautiful cities

B.many Mayan cities and temples are still standing

C.the Maya were intelligent and culturally rich people

D.the Mayan calendar was the same as European calendars小题3:Why it is said that the Mayan people lived a better life than most people of that time?

A.They had better building skills and housing conditions.

B.They believed in many gods, and honored the Mayan gods.

C.They had knowledge about tools and faming.

D.They studied about nature and the world around them.小题4:What can be the best title for this article?

A.Mayan Gods

B.Mayan Buildings

C.Productive Maya

D.Mysterious(神秘的)Maya

题型:单项选择题

—______ is the bank?            

—It's on Center Street.         [ ]

A. What    

B. How    

C. When     

D. Where

题型:单项选择题

一个数由四个亿、七个千万、三个千和五个百组成,这个数写作______,省略“亿”后面的尾数约是______亿.

题型:单项选择题

某同学在分析实验室有些药品需要密封保存的原因时,归纳出了以下两种原因:

①药品易挥发;②药品能与空气中的某些成分发生化学反应.

(l)请选择一种药品,写出一个符合原因②的化学方程式:______;

(2)药品密封保存的原因还很多,请你分析浓硫酸需要密封保存的原因:______.

题型:单项选择题

代理乡镇国库的国库存款如何计付利息?

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