简述超硬磨料立方氮化硼的性能、特点及应用。

2013年12月12日，财政部、国家税务总局印发《营业税改征增值税试点实施办法》，自2014年1月1日起在全国执行。作为国内结构性减税的重要措施，“营改增”将对以前缴纳营业税的产品或服务项目，采取增值部分纳税的原则，减少重复征税。小规模纳税人税负得以下降。此举有利于：

①维护社会公平，提高人民生活水平   

②促进我国服务行业的发展，推动经济发展方式的转变 

③增加财政收入，促进资源优化配置  

④降低中小企业税收成本，增强企业发展能力

A．①②

B．①④

C．②③

D．②④

阅读下面这首诗，完成文后题目。

白梅

（元）王冕

冰雪林中著此身，不同桃李混芳尘。

忽然一夜清香发，散作乾坤万里春。

［注释］著：置。

小题1:这首诗是从哪几方面表现梅花品格的？

小题2:“借花说理”是这首诗的一大特色，请就此赏析。

根茎呈不规则柱状，细圆柱形，断面中空;根茎节处周围着生多数细长的根。根呈细长圆柱形，并有纤细的须根。质脆，断面粉性。气香，味微辛凉的中药材是()
根茎呈细长圆柱形，节明显，质脆，断面中空。节处簇生纤细弯曲的根，有多次分枝呈毛须状。气微，味微甜的中药材是()
根茎粗短，有结节，下面及两侧簇生多数细长的根，根表面棕黄色。质脆，易折断。气微，味微苦的中药材是

A.白薇

B.白前

C.紫苑

D.威灵仙

E.徐长卿

阅读理解。

     From the earliest times, man has been interested in art. People have often worked together to collect and

save the world's art treasures.

     Fine art treasures from many countries are kept in an art museum called the Louvre in Paris, France. The

works of art have been collected by the people of France over many centuries. The Louvre has not always

been a museum. The first building was a fort (炮台). In 1190, it was the king's castle with high walls and a

round tower. It had a moat to prevent his enemies from walking in.

     Over the years, the number of buildings around the castle grew. By 1350, the castle was no longer needed

as a fort. The Louvre became a palace home for French kings and queens.

     During times of peace, new treasures were brought in. During days of war, many treasures were stolen,

and the buildings were damaged.

     When Francis I became king of France in 1515, he brought in artists from many countries. One of the

artists was Leonardo da Vinci from Italy. Da Vinci's "Mona Lisa" is the best known painting in the museum

today.

     In 1793, the Louvre became a public museum, just as it is now. It is a place where art treasures have been

saved for everyone to enjoy.

1. How long has the Louvre been a museum?

A. For over 800 years.

B. Since 1350.

C. Since 1515.

D. For over 200 years.

2. Most of the works of art in the Louvre have been collected probably_____.

A. by the French people

B. by Francis I

C. by Leonardo Da Vinci

D. by people of the world

3. From the passage we can learn that _____.

A. the Louvre was once a church as well as a palace

B. Mona Lisa is kept in Italy

C. Da VinCi once stayed in France

D. the Louvre is only a place of interest to the French people

4. Why is it good for the works of art to be kept in public museums?

A. In public museums works of art will not be stolen.

B. In public museums works of art will not be damaged.

C. In public museums artists can study the works of art.

D. In public museums everyone can enjoy the works of art.

以下器官受系统性硬化病(SSc)侵犯会导致患者出现咳嗽、气短的是（）

A.肝

B.心脏

C.肺

D.肾

E.食管