询问GWD 19-21

    In the 1930’s and 1940’s,

         African American industrial

         workers in the southern United

Line  States, who constituted 80 per-

  (5)  cent of the unskilled factory labor

force there, strongly supported

unionization.  While the American

Federation of Labor (AFL) either

excluded African Americans or

 (10)  maintained racially segregated

unions, the Congress of Industrial

Organizations (CIO) organized

integrated unions nationwide on the

basis of a stated policy of equal

 (15)  rights for all, and African American

unionists provided the CIO’s back-

bone.  Yet it can be argued that

through contracts negotiated and

enforced by White union mem-

 (20)  bers, unions—CIO unions not

         excluded—were often instrumen-

         tal in maintaining the occupational

segregation and other forms of

racial discrimination that kept

 (25)  African Americans socially and

economically oppressed during

this period.  However, recognizing

employers’ power over workers

as a central factor in African

 (30)  Americans’ economic marginal-

ization, African American workers

saw the need to join with White

     workers in seeking change despite

White unionists’ toleration of or

 (35) support for racial discrimination.

The persistent efforts of African

American unionists eventually paid

off:  many became highly effective

        organizers, gaining the respect of

 (40)     even racist White unionists by win-

ning victories for White as well as

African American workers.  African

American unionists thus succeeded

in strengthening the unions while

 (45)  using them as instruments of

African Americans’ economic

empowerment.

--------------------------------------------------------------------------------

Q21:

The passage is primarily concerned with

1. demonstrating that unions failed to address the concerns of African American workers during a particular period

2. arguing that African American workers’ participation in unions during a particular period was ultimately beneficial to them

3. contrasting the treatment of African American workers by two different labor organizations during a particular period

4. giving reasons for the success of African American unionists in winning victories for both African American and White workers during a particular period

5. questioning one explanation for the attitudes of African American workers toward unionization during a particular period

答案选B，请教如何在原文定位？另D项错在何处？拜谢~！