力的三要素是力的（）、方向、作用点。

下列离子在溶液中因发生氧化还原反应而不能大量共存的是

A．H⁺、Na⁺、HCO₃^—、Cl^—

B．H⁺、Ag⁺、NO₃^—、Cl^—

C．SO₄^2—、Na⁺、CO₃^2—、H⁺

D．NO₃^—、^—Fe²⁺、H⁺、Cl^—

阅读理解。

     You may have heard the term "the American Dream". In 1848, James W. Marshall found gold in

California and people began having golden dreams. That 19th century "American Dream" motivated

the Gold Rush and gave California its nickname of the "Golden State".

    The American Dream drove not only 1800s gold-rush prospectors(采矿者)but also waves of

immigrants throughout that century and the next. People from Europe, and a large number of Chinese,

arrived in the US in the 19th century hoping that in America they would find gold in the streets. But

most, instead, worked as railroad laborers. They created the oldest Chinatown, in San Francisco, and

gave the city a Chinese name "the old gold hill".

     In the 20th century, some critics said that it was no longer possible to become prosperous through

determination and hard work. Unfair education for students from poor families and racial discrimination

almost made the American Dream a nightmare(噩梦).

     Then, in the 1990s, California saw a new wave of dreamers in Silicon Valley. People poured their

energy into the Internet. This new chapter of the American Dream attracted many business people and

young talents from China and India to form start-ups and seek fortune in America. Better pay, a nice

house, and a rising standard of living will always be attractive. However, the new American Dream is

no longer just about money. It encourages Americans to consume wisely to protect the environment,

improve the quality of life, and promote social justice.

    The Governor of California, Arnold Schwarzenegger has become the model of the new American

Dream. After years of hard work, he grew from a poor young man from Austria into a super movie

star and then a governor. Many people hope his story can save the American Dream and give California

a brighter future.

1. The "American Dream" was appealing to _______________.

A. Americans only.              

B. Chinese and Indians .    

C. Europeans.                  

D. people all over the world

2. It can be inferred that ____________.  

A. America's golden dream could never be realized

B. different times have different themes of the American dream

C. America's golden dream brought great fortune to Chinese immigrants

D. determination and hard work are the best way to realize the American dream

3. Why did most of the early immigrants work as railroad laborers?

A. Because they could earn more money as railroad laborers.

B. Because they thought railroad was the first step to find gold.

C. Because railroad laborers were greatly honored at that time. 

D. Because they had to make a living by working as railroad laborers.

4. The underlined sentence in the last paragraph indicates that ___________.

A. most of the immigrants to America don't reach their previous goals

B. the dream of seeking fortune in America is easy to realize

C. the success of Arnold Schwarzenegger is a common example of the immigrants

D. the immigrants have made great contributions to California

5. Which may be the best title of the passage?

A. Waves of Immigrants to America            

B. Hard Work Leads to Success

C. Changes of America's Golden Dream        

D. Make Fortunes Abroad

压裂施工记录三条基本曲线是压力、密度和（）。

A.砂比

B.总液量

C.排量

D.水马力

人文精神的形成和嬗变包括（）

A.态度

B.政治

C.经济

D.文化发展现状

白银的使用最早出现在（）代

A、秦

B、汉

C、晋

D、隋