以下选项中不是S7-200 PLC中模拟量模块EM231具体型号的是（）。

此题为判断题(对，错)。

A、输入模拟量的量程

B、输入模拟量的分辨率

C、输出模拟量的量程

D、输出模拟量的分辨率;

A.EM277

B.CP243-1

C.EM221

D.EM231

A、EM277

B、EM231

C、EM241

D、EM253

A、EM253

B、CP243-1

C、EM277

D、EM231

在图所示的降压斩波电路中，已知E=200V，R=10Ω，L值极大，蓄电池电压E_M=50V，T=140μs，t_on=20μs，计算输出电压平均值U_o、输出电流平均值I_o。

  

On September 7, 2001, a 68-year-old woman in Strasbourg, France, had her gall bladder (胆囊) removed by surgeons' operating, via computer from New York. It was the first complete telesurgery procedure performed by surgeons nearly 4, 000 miles away from their patient.

In New York, Marescaux teamed up with surgeon Michel Gagner to perform. the historic long-distance operation. A high-speed fiber-optic service provided by France Telecom made the connection between New York and Strasbourg. The two surgeons controlled the instruments using an advanced robotic surgical system, designed by Computer Motion Inc that enabled the procedure to be minimally invasive. The patient was released from the hospital after about 48 hours and regained normal activity the following week. The high-speed fiber-optic connection between New York and France made it possible to overcome a key obstacle to telesurgery time delay. It was crucial that a continuous time delay of less than 200 milliseconds be maintained throughout the operation, between the surgeon's movements in New York and the return video (from Strasbourg) on his screen. The delay problem includes video coding, decoding and signal transmission time.

France Telecom's engineers achieved an average time delay of 150 milliseconds. "I felt as comfortable operating on my patient as if I had been in the room," says Marescaux.

The successful collaboration (合作) among medicine, advanced technology, and telecomm unications is likely to have enormous implications for patient care and doctor training. Highly-skilled surgeons may soon regularly perform. especially difficult operations through long-distance procedures. The computer systems used to control surgical movement can also lead to a breakthrough in teaching surgical techniques to a new generation of physicians. More surgeons-in-training will have the opportunity to observe their teachers in action in telesurgery operating rooms around the world.

Marescaux describes the success of the remotely performed surgical procedure as the beginning of a "third revolution" in surgery within the last decade. The first was the arrival of minimally invasive surgery, enabling procedures to be performed with guidance by a camera, meaning that the abdomen (腹部) and thorax (胸腔) do not have to be opened. The second was the introduction of computer-assisted surgery, where complicated software algorithms (计算法) enhance the safety of the surgeon's movements during a procedure, making them more accurate, while introducing the concept of distance between the surgeon and the patient. It was thus natural to imagine that this distance--currently several meters in the operating room--could potentially be up to several thousand kilometers.

The title that best expresses the main idea is ______.

A．How the Second Revolution in Surgery Comes Out

B．The Telesurgery Revolution

C．A Patient Was Saved

D．Dream Comes True

Fake products are very harmful, but they still enjoy great popularity. They have brought about a lot of social problems. Why can they get so widespread? What harmfulness do they bring to people? How to solve the problem? Choose one or two aspects to talk about. Write a composition of about 200 words on the following topic: The Harmfulness of Fake Products

Optimists Really Do Live Longer, Say Scientists

1. For the philosopher Arthur Schopenhauer optimism was fundamentally wrong banal and corrupting, while the father of psychoanalysis Sigmund Freud simply declared it to be neurotic.

2. Experience shows that looking on the bright side of life does have advantages and recent scientific evidence points to the positive mindset(思想倾向) as being beneficial to health. In other words optimists live longer.

3. That was the conclusion reached by experts at the Mayo Clinic in the US State of Minnesota who evaluated answers given by people to a set of questions in the 1960s. Of the 729 candidates, 200 had died and according to scientists, there were a disproportionate number of pessimists among them.

4. The points more on the pessimism scale-that was the difference between "slightly pessimistic" and "averagely pessimistic"-were enough to boost a person's chances of dying by 19 percent, according to the study by prominent psychologist Martin Seligman of the University of Pennsylvania.

5. The study does not say why pessimists die but an older survey taken among children in San

Francisco and Los Angeles makes it clear that personal attitude towards the world is a key factor in the longevity equation.

6. The latest evidence to support the theory that optimists tend to cope better with illness of all kinds has been provided by professor Ralf Schwarzer of Berlin's Free University who questioned 600 heart and lung patients. His conclusion: optimists recover more swiftly from operations than their pessimistic counterparts, tend to be happier after treatment and return to work more swiftly.

7. There have been suggestions that optimists do not stay healthier but rather turn into optimists later because they enjoy good health. Numerous surveys have taken into account a person's state of health at the outset (最初) and the effect remains the same.

8. Studies have shown that optimists do not blind themselves to reality either. They thus interpret it in a positive way. "Sublimating (vi.升华) and denying things tend to alter reality but illusions are a way of seeing reality in the best light," said California.

9. German science journal Bild der Wissenschaft, which carries a major article on the topic in its current March issue, commented on "the right attitude" to having a tumor.

10. It seems psychotherapy can go some way towards extending the life span and life quality of a sick person although a complete recovery using psychological technique alone is unlikely.

11. Doctors like, however, to point to the example of US cycling professional Lance Armstrong, who was seriously ill with cancer, but whose unshakeable optimism helped him to take the top trophy twice at cycling's premiers Tour de France.

12. The magazine also quoted a study by Sheldon Cohens of the Caregie Mellon University in Pittsburgh: 420 volunteers were deliberately infected with strains of various common cold viruses. A day later checks were carried out to see who had caught a cold.

13. The results showed that in the case of people who had satisfactory, long-term relations with friends, neighbors or colleagues, the virus was less likely to trigger a cold. Of people with three of fewer firm relationships 62 percent became ill compared with only 35 percent of those who had six or more close human links.

A. Quicker recovery from illness

B. A longer life for optimists

C. Relationship between good health and optimism

D. A positive way of understanding reality

E. Optimism and pessimism

F. Optimists with illusions

Paragraph 2______.