问题 选择题

下列有关叙述,正确的是

A.肺炎链球菌是多个细胞组成的个体,能产生一串孢子进行生殖

B.真菌大多是多细胞的丝状体,有核膜把细胞核和细胞质分隔开来

C.真菌大多有菌丝伸入营养物质内吸收水和无机物,制造有机物

D.绿脓杆菌噬菌体可用来控制烧伤病人感染绿脓杆菌,这种噬菌体属于动物病毒

答案

答案:B

题目分析:A、肺炎链球菌是细菌,细菌是单细胞个体,靠分裂进行繁殖,错误,不符合题意;

B、真菌有单细胞的,有多细胞的,细胞结构有:细胞壁、细胞膜、细胞质、细胞核、液泡,正确,符合题意;

C、真菌的细胞结构没有叶绿体,所以不能制造有机物,错误,不符合题意;

D、绿脓杆菌噬菌体寄生在细菌内,属于细菌病毒,错误,不符合题意;

故选B。

单项选择题
单项选择题

Come on, my fellow white folks, we have something to confess. Out with it, friends, the biggest secret known to whites since the invention of powdered rouge: welfare is a white program. The numbers go like this: 61% of the population receiving welfare, listed as "means-tested cash assistance" by the Census Bureau, is identified as white, while only 33% is identified as black. These numbers notwithstanding, the Republican version of "political correctness" has given us "welfare cheat" as a new term for African American since the early days of Ronald Reagan.

Our confession surely stands: white folks have been gobbling up the welfare budget while blaming someone else. But it’s worse than that. If we look at Social Security, which is another form of welfare, although it is often mistaken for an individual insurance program, then whites are the ones who are crowding the trough. We receive almost twice as much per capita, for an aggregate advantage to our race of $10 billion a year--much more than the $3. 9 billion advantage African American gain from their disproportionate share of welfare. One sad reason: whites live an average of six years longer than African Americans, meaning that young black workers help subsidize a huge and growing "over-class" of white retirees. I do not see our confession bringing much relief. There’s a reason for resentment, though it has more to do with class than with race. White people are poor too, and in numbers far exceeding any of our more generously pigmented social groups. And poverty as defined by the government is a vast underestimation of the economic terror that persists at incomes--such as $ 20,000 or even $ 40,000 and above--that we like to think of as middle class.

The problem is not that welfare is too generous to blacks but that social welfare in general is too stingy to all concerned. Naturally, whites in the swelling "near poor" category resent the notion of whole races supposedly frolicking at their expense. Whites, near poor and middle class, need help too--as do the many African Americans.

So we white folks have a choice. We can keep pretending that welfare is black program and a scheme for transferring our earnings to the pockets of shiftless, dark-skinned people. Or we can clear our throats, blush prettily and admit that we are hurting too--for cash assistance when we’re down and out, for health insurance, for college aid and all the rest. Racial scapegoating has its charms, I will admit: the surge of righteous anger, even the fun--for those inclined--of wearing sheets and burning crosses. But there are better, nobler sources of white pride, it seems to me. Remember this: only we can truly, deeply blush.

White folks in U.S. are at a greater advantage in that()

A. they obtain more benefits from welfare

B. they show contempt for African Americans

C. they blame the blacks for welfare theft

D. they have a choice to their best interests