【正文】 GWD9Q20:Which of the following most logically pletes the reasoning?Either food scarcity or excessive hunting can threaten a population of animals. If the group faces food scarcity, individuals in the group will reach reproductive maturity later than otherwise. If the group faces excessive hunting, individuals that reach reproductive maturity earlier will e to predominate. Therefore, it should be possible to determine whether prehistoric mastodons became extinct because of food scarcity or human hunting, since there are fossilized mastodon remains from both before and after mastodon populations declined, and ______.A. there are more fossilized mastodon remains from the period before mastodon populations began to decline than from after that periodB. the average age at which mastodons from a given period reached reproductive maturity can be established from their fossilized remainsC. it can be accurately estimated from fossilized remains when mastodons became extinctD. it is not known when humans first began hunting mastodonsE. climate changes may have gradually reduced the food available to mastodonsGWD9Q21Q23 G9Q21Q23 In the 1930’s and 1940’s, African American industrial workers in the southern United States, who constituted 80 percent of the unskilled factory labor force there, strongly supported unionization. While the American Federation of Labor (AFL) either excluded African Americans or maintained racially segregated unions, the Congress of Industrial Organizations (CIO) organized integrated unions nationwide on the basis of a stated policy of equal rights for all, and African American unionists provided the CIO’s backbone. Yet it can be argued that through contracts negotiated and enforced by White union members, unions—CIO unions not excluded—were often instrumental in maintaining the occupational segregation and other forms of racial discrimination that kept African Americans socially and economically oppressed during this period. However, recognizing employers’ power over workers as a central factor in African Americans’ economic marginal ization, African American workers saw the need to join with White workers in seeking change despite White unionists’ toleration of or support for racial discrimination. The persistent efforts of African American unionists eventually paid off: many became highly effective organizers, gaining the respect of even racist White unionists by winning victories for White as well as African American workers. African American unionists thus succeeded in strengthening the unions while using them as instruments of African Americans’ economic empowerment.GWD9Q21 G9Q21:The passage is primarily concerned withA. demonstrating that unions failed to address the concerns of African American workers during a particular periodB. arguing that African American workers’ participation in unions during a particular period was ultimately beneficial to themC. contrasting the treatment of African American workers by two different labor organizations during a particular periodD. giving reasons for the success of African American unionists in winning victories for both African American and White workers during a particular periodE. questioning one explanation for the attitudes of African American workers toward unionization during a particular periodGWD9Q22 G9Q22:According to the passage, which of the following was true of many racist White unionists during the period discussed in the passage?A. Their attitudes toward African American union organizers changed once they recognized that the activities of these organizers were serving workers’ interests.B. They were a powerful element in the southern labor movement because they constituted the majority of the unskilled factory labor force in the southern United States.C. They persisted in opposing the CIO’s adoption of a stated policy of equal rights for all.D. Their primary goal was to strengthen the negotiating power of the unions through increasing White union membership.E. Their advocacy of racial discrimination hampered unions in their efforts to gain more power for workers.GWD9Q23 G9Q23:The author of the passage suggests which of the following about African American workers who participated in union activities in the 1930’s and 1940’s?A. They believed that the elimination of discrimination within unions was a necessary first step toward the achievement of economic advancement for African Americans.B. They belonged exclusively to CIO unions because they were excluded from AFL unions.C. They believed that the economic advancement of African American workers depended on organized efforts to empower all workers.D. Some of them advocated the organization of separate African American unions because of discriminatory practices in the AFL and the CIO.E. Many of them did not believe that White unionists in CIO unions would tolerate or support racial discrimination against African American workers.GWD9Q24:For similar cars and drivers, automobile insurance for collision damage has always cost more in Greatport than in Fairmont. Police studies, however, show that cars owned by Greatport residents are, on average, slightly less likely to be involved in a collision than cars in Fairmont. Clearly, therefore, insurance panies are making a greater profit on collisiondamage insurance in Greatport than in Fairmont.Which of the following is an assumption on which the argument dep