如图所示，横轴表示细胞分裂时期，纵轴表示一个细胞核中DNA含量或染色体数目的变化情况。据图分析，表示有丝分裂过程中DNA含量变化、染色体数目变化和减数分裂过程中DNA含量变化、染色体数目变化的曲线依次是( )
| A．④②①③ | B．①④②③ | C．④①②③ | D．①②③④ |
已知(2，5)、(4，5)是抛物线y=ax2＋bx＋c上的两点，则这个抛物线的对称轴方程是
A．x= ． | B．x=2． | C．x=4． | D．x=3． |
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 (激发起) the Gold Rush and gave California its nickname of the "Golden State".
The American Dream drove not only 1800s gold-rush prospectors 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 labourers. 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.
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 fortunes 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 movie superstar and then governor. Many people hope his story can save the American Dream and give California a brighter future.
【小题1】 It can be inferred that _____.
【小题2】Why did most of the early immigrants work as railroad laborers?
【小题3】The underlined sentence “his story can save the American Dream” (in the last paragraph) indicates that _____.
【小题4】What’s the best title of the passage?
The American Dream drove not only 1800s gold-rush prospectors 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 labourers. 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.
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 fortunes 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 movie superstar and then governor. Many people hope his story can save the American Dream and give California a brighter future.
【小题1】 It can be inferred that _____.
| A．America’s golden dream could never be realized |
| B．America’s golden dream had bought great fortunes to Chinese immigrants |
| C．each period of time has its own taste of the American dream |
| D．determination and hard work are the best way to realize the American dream |
| A．Because they could earn more money as railroad laborers. |
| B．Because they had to make a living by working as railroad laborers. |
| C．Because they thought railroad was the first step to find gold. |
| D．Because railroad laborers were greatly honored at that time. |
| A．the dream of seeking fortunate in America is easy to realize |
| B．most of the immigrants to America don’t reach their previous goal |
| C．the success of Arnold Schwarzenegger is among the common examples of the immigrants |
| D．the immigrants have made great contributions to California |
| A．Wave of Immigrants to America | B．Make Fortunes Abroad |
| C．Hard Work Leads to Success | D．Changes of America’s Golden Dream |
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 (激发起) the Gold Rush and gave California its nickname of the "Golden State".
The American Dream drove not only 1800s gold-rush prospectors 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 labourers. 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.
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 fortunes 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 movie superstar and then governor. Many people hope his story can save the American Dream and give California a brighter future.
【小题1】 It can be inferred that _____.
【小题2】Why did most of the early immigrants work as railroad laborers?
【小题3】The underlined sentence “his story can save the American Dream” (in the last paragraph) indicates that _____.
【小题4】What’s the best title of the passage?
The American Dream drove not only 1800s gold-rush prospectors 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 labourers. 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.
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 fortunes 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 movie superstar and then governor. Many people hope his story can save the American Dream and give California a brighter future.
【小题1】 It can be inferred that _____.
| A．America’s golden dream could never be realized |
| B．America’s golden dream had bought great fortunes to Chinese immigrants |
| C．each period of time has its own taste of the American dream |
| D．determination and hard work are the best way to realize the American dream |
| A．Because they could earn more money as railroad laborers. |
| B．Because they had to make a living by working as railroad laborers. |
| C．Because they thought railroad was the first step to find gold. |
| D．Because railroad laborers were greatly honored at that time. |
| A．the dream of seeking fortunate in America is easy to realize |
| B．most of the immigrants to America don’t reach their previous goal |
| C．the success of Arnold Schwarzenegger is among the common examples of the immigrants |
| D．the immigrants have made great contributions to California |
| A．Wave of Immigrants to America | B．Make Fortunes Abroad |
| C．Hard Work Leads to Success | D．Changes of America’s Golden Dream |
下面有关硅的叙述中，正确的是
0 65590 65598 65604 65608 65614 65616 65620 65626 65628 65634 65640 65644 65646 65650 65656 65658 65664 65668 65670 65674 65676 65680 65682 65684 65685 65686 65688 65689 65690 65692 65694 65698 65700 65704 65706 65710 65716 65718 65724 65728 65730 65734 65740 65746 65748 65754 65758 65760 65766 65770 65776 65784 235360
| A．硅原子既不易失去电子又不易得到电子，主要形成四价的化合物 |
| B．硅是构成矿物和岩石的主要元素，硅在地壳中的含量在所有的元素中居第一位 |
| C．硅的化学性质不活泼，在自然界中可以以游离态存在 |
| D．二氧化硅在电子工业中，是最重要的半导体材料 |