Critical Reasoning

Pls guide with the reasoning for the answers.....Have trouble understanding the given options (taken from cr 1000)

2. Which of the following best completes the passage below?
One tax-reform proposal that has gained increasing support in recent years is the flat tax, which would impose a uniform tax rate on incomes at every level. Opponents of the flat tax say that a progressive tax system, which levies a higher rate of taxes on higher-income taxpayers, is fairer, placing the greater burden on those better able to bear it. However, the present crazy quilt of tax deductions, exemptions, credits, and loopholes benefits primarily the high-income taxpayer, who is consequently able to reduce his or her effective tax rate, often to a level below that paid by the lower-income taxpayer. Therefore, ______
(A) higher-income taxpayers are likely to lend their support to the flat-tax proposal now being considered by Congress
(B) a flat-tax system that allowed no deductions or exemptions would substantially increase actual government revenues
(C) the lower-income taxpayer might well be penalized by the institution of a flat-tax system in this country
(D) the progressive nature of our present tax system is more illusory than real
(E) the flat tax would actually be fairer to the lower-income taxpayer than any progressive tax system could be

Ans:D

7. If A, then B.
If B, then C.
If C, then D.
If all of the statements above are true, which of the following must also be true?
(A) If D, then A.
(B) If not B, then not C.
(C) If not D, then not A.
(D) If D, then E.
(E) If not A, then not D.

Ans:C

14. Which of the following, if true, would most strengthen the argument above?
(A) New resource deposits are constantly being discovered.
(B) The United States consumes one-third of all resources used in the world.
(C) Other countries need economic development more than the United States does.
(D) Other countries have agreed to hold their resource consumption at present levels.
(E) The United States has been conserving resources for several years.
Ans:B

19. Which of the following, if true, would most seriously weaken the author’s conclusion?
(A) The plastic produced by the process is considerably lighter, stronger, and more watertight than wood.
(B) The wood used in producing the plastic is itself in increasingly short supply.
(C) The cost of the manufacturing process of the plastic increases the cost of producing a sailboat hull by 10 to 15 percent.
(D) Much of the cost of the research that developed the new process will be written off for tax purposes by the chemical company.
(E) The development of the new plastic is expected to help make the chemical company an important supplier of boat-building materials.
Ans:A

2.However, the present crazy quilt of tax deductions, exemptions, credits, and loopholes benefits primarily the high-income taxpayer, who is consequently able to reduce his or her effective tax rate, often to a level below that paid by the lower-income taxpayer
The above statement is made in qualification of progressive system .

7. Remember that If A imples B then not B imples not A.
Hope this answers

14. If United states consumes 1/3rd of the resources,definitely it has to keep its consumption at present levels to avoid depletion of resources.

19.IF A is correct,this implies that development of making plastic is worth.As the author says whats the use of making it if the wood suffice all requirements.But if you make a product and it is better in all respects then its worth making.