关于谷氨胺酰（Gln），叙述正确的是（） A.Gln为人体含量最丰富的必需氨基酸 B

Sometimes _______turns off the lights in the classroom because every body thinks somebody will do it.

A．anybody

B．somebody

C．nobody

D．everybody

Johann Gutenberg, who worked as a goldsmith(金匠)，took what has already been discovered, and created a small invention that changed history. He created a machine that allowed him to move small blocks of letters in such a way that written material could be printed and mass-produced. Few people could read before Johann Gutenberg made the invention, but once books became less expensive, more Europeans could read and write.

Block printing existed long before Gutenberg. The Chinese had been using wood blocks to print books as early as 868, but a new set of woodcuts(木刻印版) had to be made for each book. Producing one book was not easy; producing all kinds of books was more difficult.

Writing ink dates from about 2500 BC in Egypt and China. Johann Gutenberg use an oil-base printing ink that would last longer than other inks used in his time. We don’t know much about Gutenberg because he was not famous during his lifetime. He was born in Germany about 1400. In 1448, Gutenberg developed signatures for each number, letter, and punctuation mark(标点符号). He then built the molds (模型) to hold the signatures in place. Johann Gutenberg published the first mass-produced book: a 1,282 page Bible. To this day, more copies of the Bible have been printed the any other book.

Copies of Gutenberg’s invention spread throughout Europe, but the German goldsmith did not get rich from his invention. Some officials denounced the invention of printing because they feared that it would spread bad ideas. By 1500 there 1,700 printing presses in Europe. The presses had already produced about 20 million volumes of 40,000 different books.

小题1:What happened after Johann Gutenberg’s invention?

A．People could afford to read books.

B．People became interested in inventing.

C．It was still difficult to print all kinds of books.

D．Punctuation mark began to be used in printing.小题2:Compared with block printing in China, Johann Gutenberg’s method __________.

A．was difficult to run.

B．needed harder paper

C．used a new kind of ink

D．was put into use earlier小题3:The underlined word “denounced” in the paragraph means __________.

A．fought against

B．accepted

C．laughed at

D．supported小题4:What is the best title for the passage?

A．A famous 1,282 page Bible

B．The life of a famous inventor

C．An invention that changed history

D．The development of printing

从地上搬起重物时，应该采取在双膝伸直位时弯腰搬物。

波斯纳提出了一个教师成长公式是_____。

关于普通水泥的硬化，说法正确的是（）。

A.在水中体积收缩

B.在水中体积增大

C.在空气中体积增大

D.在空气中体积不变