问题 单项选择题

对疑有心内粘液瘤的患者,超声诊断主要应用那种技术进行确诊()。

A.频谱多普勒检测心腔与大动脉间有无异常血流

B.对心房肿瘤用多普勒技术检测收缩期血流有无异常

C.二维超声显示肿瘤的部位、大小、活动性与室壁的关系

D.彩色多普勒观察有无心内分流血流

E.M型超声观察心腔壁的运动

答案

参考答案:C

单项选择题
单项选择题

It was the best of times or, depending on your political and philosophical outlook, one of the foulest and most depraved. Rebellion seemed to be leaping from city to city, continent to continent, by some fiery process of contagion. Radical students filled the streets of Mexico city, Berlin, Tokyo, Prague. In the U. S. , Chicago swirled into near anarchy as cops battled antiwar demonstrators gathered at the Democratic Convention. And everywhere from Amsterdam to Haight-Ashbury, a generation was getting high, acting up.

So, clearly, it was the year from hell--a collective "dive into extensive social and personal dysfunction," as the Wall Street Journal editorialized recently. Or, depending again on your outlook, a global breakthrough for the human spirit. On this, the 25th anniversary of 1968, probably the only thing we can all agree on is that ’68 marks the beginning of the "culture wars," which have divided America ever since.

Both the sides of the "culture wars" of the ’80s and ’90s took form in the critical year of’68. The key issues are different now--abortion and gay rights, for example, as opposed to Vietnam and racism--but the underlying themes still echo the clashes of ’68: Diversity vs. conformity, tradition vs. iconoclasm, self-expression vs. deference to norms. "Question authority," in other words, vs. "Father knows best."

The 25th anniversary of ’68 is a good time to reflect, calmly and philosophically, on these deep, underlying choices. On one hand we know that anti-authoritarianism for its own sake easily degenerates into a rude and unfocused defiance: Revolution, as Abbie Hoffman put it, "for the hell of it." Certainly ’68 had its wretched excesses as well as its moments of glory: the personal tragedy of lives undone by drugs and sex, the heavy cost of riots and destruction. One might easily conclude that the ancient rules and hierarchies are there for a reason--they’re worked, more or less, for untold millenniums, so there’s no point in changing them now.

But it’s also true that what "worked" for thousands of years may not be the best way of doing things. Democracy, after all, was onee a far-out, subversive notion, condemned by kings and priests. In our own country, it took all kinds of hell-raising, including a war, to get across the simple notion that no person is morally entitled to own another. One generation’s hallowed tradition--slavery, or the divine right of kings--may be another generation’s object lesson in human folly.

’68 was one more awkward, stumbling, half-step forward in what Dutschke called the "long march" toward human freedom. Actually, it helped inspire the worldwide feminist movement.

Different generations of Americans may be best divided with regard to()

A. their world outlook

B. long-held traditions

C. their own privileges

D. social institutions