问题 单项选择题

某厂共有机器10台,生产某种商品每台机器的产能为10件,现有一批500件的这类商品要生产,机器每天工作时间为24小时,损耗为2%,生产这批商品需要()小时。

A.5

B.5.1

C.4.9

D.5.2

答案

参考答案:D

单项选择题
阅读理解

阅读理解

     Imagine a classroom missing the one thing that's long been considered a necessary part to reading

and writing paper.No notebooks, no textbooks, no test paper.Nor are there any pencils or pens, which

always seem to run out of ink at the critical moment.A"paperless classroom"is what more and more

schools are trying to achieve.

     Students don't do any handwriting in this class.Instead, they use palm size, or speciallydesigned

computers.The teacher downloads texts from Internet libraries and sends them to every student's

personal computer.

      Having computers also means that students can use the Web.They can look up information on any

subject they're studying from maths to social science.

     High school teacher Judy Herrell in Florida, US, described how her class used the Web to learn

about the war in Afganistan(阿富汗) over one year ago.

      "We could touch every side of the country through different sites from the forest to refugee camps

(难民营), "she said."Using a book that's three or four years old is impossible."

      And exams can go online too.At a high school in Tennessee, US, students take tests on their own

computers.The teacher records the grades on the network for everyone to see and then copies them to

his own electronic grade book.

      A paperless classroom is a big step towards reducing the waste of paper. High school teacher

Stephanie Sorrell in Kentucky US said she used to give about 900 pieces of paper each week to each

student.

      "Think about the money and trees we could save with the computers, "she said. But, with all this

technology, there's always the risk that the machines will break down. So, in case of a power failure or

technical problems, paper textbooks are still widely available for these hitech students.

1. What does the part of the last but one sentence in the first paragraph, "run out of ink at the critical

     moment" mean?

A. Pens may not write welt at the critical moment.

B. Pens get lost easily, so you may not find them at the critical moment.

C. Pens may have little or no ink at the critical moment.

D. Pens use ink, while pencils don't.

2. In a paperless classroom, what is a must?

A. Pens.                            

B. Computers.

C. Information.                                

D. Texts.

3. The high school teacher, Judy Herrell, used the example of her class to show that________.

A. the Web could take them everywhere

B. the Web taught them a lot

C. the Web is a good tool for information

D. the Web, better than the textbooks, can give the latest and comprehensive(全面的) information

4. The paperless classrooms will benefit ________ the most.

A. students                                  

B. teachers  

C. trees                                      

D. computers

5. What does the phrase in the last paragraph, "break down", mean?

A. Break into pieces.                          

B. Stop working.

C. Fall down.                                

D. Lose control.