若要对电视机中的行、场扫描波形进行定性、定量地检测，应使用的_爱下问搜题

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问题填空题

若要对电视机中的行、场扫描波形进行定性、定量地检测，应使用的仪器为（）。

答案

参考答案：示波器

填空题

Happy 75th Birthday, Social Security

1. On its 75th anniversary Social Security is once again under attack and so are its defenders. Those who would axe benefits are spreading myths designed to make you think there is a looming crisis. Well, it is just not true. The stark reality is that it will be several decades before the program encounters any financial problems. The program’s trust fund will have a ＄4.3 trillion surplus by 2023, and can pay all its obligations for decades to come. And strengthening Social Security is easy—making the very rich pay their fair share by lifting the cap on contributions by the wealthy would allow the program to pay all its obligations indefinitely.
2. Social Security was a centerpiece of FDR(Franklin Delano Roosevelt)’s New Deal reforms that helped this country recover from the Great Depression. These programs provided Americans a measure of dignity and hope and lasting security against the vicissitudes of the market and life. FDR therefore accomplished what the venerable New Deal historian David Kennedy says is the challenge now facing President Obama—a rescue from the current economic crisis which will also make us "more resilient to face those future crises that inevitably await us."
3. This anniversary is also a reminder of how major social reforms in this country have come about—in fits and starts. As former Clinton adviser Paul Begala observed in a Washington Post op-ed, "No self-respecting liberal today would support Franklin Roosevelt’s original Social Security Act... If that version of Social Security were introduced today, progressives like me would call it cramped, parsimonious, mean-spirited and even racist. Perhaps it was all those things. But it was also a start. And for 74 years we have built on that start."
4. Indeed when Social Security was first passed it left out African Americans and migrant workers. It was an imperfect piece of legislation but one that progressives built on to create the program we know today—a program like Medicare—that people feel an emotional connection to and will fight to protect. A new campaign from MoveOn and Campaign for America’s Future will tap into that energy, enlisting candidates to pledge their support to Social Security this election season—opposing any cuts in benefits, including raising the retirement age. And these candidates would be wise to pay attention: A just-released poll shows that 65% of voters reject raising the retirement age to 70. And a separate AARP (American Association of Retired Persons) poll shows the vast majority oppose cutting Social Security to reduce the deficit, and 50% of non-retired adults are willing to pay more now in payroll taxes to ensure Social Security will be there when they retire.
5. Progressives can also mark this anniversary by not only rededicating themselves to defending Social Security, but also going on the offensive to expand and improve our social security system to provide economic security for everyone.

Roosevelt’s Social Security Act paved the way for ______.

单项选择题

下列哪种说法更科学（）？

A、聚集光斑尺寸越小，说明激光束空域质量越好

B、M2因子越小，说明激光束空域质量越好

C、远场发散角越小，说明激光束空域质量越好