问题 单项选择题

为了消除CRT显示器的闪烁现象,可采用的方法是

A.提高刷新频率,减少余辉时间
B.提高刷新频率,增加余辉时间
C.减少刷新频率,减少余辉时间
D.减少刷新频率,增加余辉时间

答案

参考答案:B

解析: 本题考查多媒体输入输出设备中CRT显示器的相关知识。
CRT显示器是一种光栅图像显示器,它的工作原理为:高速的电子束由电子枪发出,经过聚集系统、加速系统和磁偏转系统就会达到荧光屏的特定位置。荧光物质在高速电子的轰击下发生电子跃迁,即电子吸收到能量从低能态变成高能态。因为所有的电子会很快回到低能态,为了保持显示稳定的画面,必须不断地发射电子束。刷新一次即电子束从上到下将荧光屏扫描一次。刷新频率达到60Hz时,人眼感觉屏幕不闪烁;刷新频率达到75Hz以上,人眼感觉比较舒服。
根据题意,为了消除CRT显示器的闪烁现象,可采用的方法是提高刷新频率,增加余辉时间。

写句子
单项选择题

Henry Kissinger may be the most successful, certainly the most flamboyant, Secretary of State to hold that office in modern times. When he was appointed in the late 1960’s, there were no American ties with Communist China, Vietnam and Berlin seemed ready to draw the United States into a third world war, and Russia was seen as "the enemy".

But all this has changed, and Henry Kissinger caused much of the change; in 1971, he made his first trip to China, a trip that was the beginning of the current ties between the United States and China. He brought the United States and Russia closer together on major issues by the policy he called "detente", literally meaning a relaxation. His philosophy was always to talk and to bring together. With these two policies, Kissinger did much to draw attention away from any possible Russia-American friction.

In 1973 he made his first visit to Egypt. Here he was able to begin U.S. relations with Egypt. He used his contact later to begin the sort of talks that the American press called "shuttle diplomacy". For ninety-nine days, he "shuttled" back and forth on flights between Cairo and Jerusalem to work out a step-by-step withdrawal of Israeli troops from the Sinai desert. His wit, his careful approach to detail, and his presence made "shuttle diplomacy" work. It was the only successful approach to Mid-east peace in the thirty years since the state of Israel was founded.

Another major work was the Strategic Arms Limitation Talk. Though his term in office passed with the treaty unsigned, Kissinger left a draft of the treaty to which the Russians had already agreed. The SALT treaty spelled out a one-tenth reduction in nuclear arms, a major accomplishment by any standard, even if one does not consider all the other conditions and limitations included in the treaty.

Even though he successfully helped bring an end to the Vietnam War, Kissinger’s final days in office were affected, as was the entire executive branch in one way or another, by the scandals of the Nixon White House. Kissinger’s critics point to his role in placing wiretaps on the phones of reporters and officials and to what they consider his "high-handed" approach to setting foreign policy. But Kissinger, during the last few months of the Nixon presidency, limited the effects of American domestic problems on our foreign policy. He continued talks in the Middle East. He continued close contact with the Soviet Union.

History will decide in the final view, as Kissinger--and many presidents--often said, on the value of his service. Whatever they decide, whether his actions are finally to be considered wise or foolish, he had a personal vision that will he difficult to match.

According to the context, the word "flamboyant" most likely means()

A. notorious

B. ambiguous

C. showy

D. arbitrary