1.Advertising are appreciated by manufactures because they     .

A.  advise them on ways of giving a product customer—appeal

B.  accept responsibility for giving a product customer—appeal

C.  advise them on the best time to go ahead with production

D.  consult them during the design and development stages

2.The passage tells us that some manufacturers, instead of changing their product, would prefer to change its     .

A.production cost                  B.quality

C.market value                    D.appeal

3.According to the passage, doctors are most successful when they are     .

A.authoritative                    B.logical

C.emotional                      D.scientific

4.According to the passage, doctors are most successful when they are     .

A.  it makes their advertisements more conspicuous

B.  it makes their advertisements more convincing