27. The first paragraph tells us that a new product is _____ .
A)usually introduced to satisfy different tastes
B)often more expensive than old ones
C)often inferior to old ones at first
D)not easily accepted by the public

28. Marketers need to know which of the four stages a product is in so as to __________ .
A)work out marketing policies                C)promote its production
B)increase its popularity                    D)speed up its life cycle

29. The author mentions the example of "backpacks"(Line 4, Para.2 ) to show the importance of _______ .
A)increasing usage among students               C)pleasing the young as well as the old
B)exploring new market sections                 D)serving both military and civil needs

30. In order to recover their share of the world market, U.S. auto makers are _______  .
A)improving product quality                     C)re-positioning their product in the market
B)modernizing product style                     D)increasing product features