CBC is a famous air company which has over twenty planes carrying passengers and goods, flying along 12 fixed lines all over the world. Its service is very good but some passengers are still not satisfied with it and that is why in 2004 and 2005 the company received letters of complaints from consumers or passengers who pointed out over a dozen kind of problems which are divided in groups in the following table. Those concerning passengers’ things carried on the plane are baggage problems. Customer service refers to service work which passengers are not satisfied with. Overselling of tickets is about the fact that more seats are sold and as a result the plane is too crowded to be safe. Refund problems appear when passengers fail to receive the money paid back to them because of what they have lost. Fares are problems concerning the price of tickets.  
Consumer Complaints Received By the CBC

Category	2004	2005
Flight problems	20.2%	22.1%
Baggage	18.3%	21.8%
Customer service	3.1%	11.3%
Over sales of seats	10.5%	11.8%
Refund problems	10.1%	8.1%
Fares	6.4%	6.0%
Reservation & Ticketing	5.8%	5.6%
Tours	3.3%	2.3%
Smoking	3.2%	2.9%
Advertising	1.2%	1.01%
Credit	1.0%	0.8%
Special passengers	0.9%	0.9%
Others	6.0%	5.3%
Total Number of Complaints	2,988	1,792

About how many complaints about Credit were received by the CBC in 2004?

A．28

B．29

C．30

D．31

By about what percentage did the total number of complaints decrease from 2004 to 2005?

A．40%

B．60%

C．75%

D．100%

If the circle graphs below show total consumer complaints for 2004, which graph shows a dark part that is about Flight problems and Refund problems together?

Which of the following statements can be inferred from the table?
a. In 2004 and in 2005, complaints about Flight problems, Baggage, and Customer service
together took more than 40 percent of all consumer complaints received by the CBC Company.
b .The number of special passengers complaints was unchanged from 2004 to 2005.
c .From 2004 to 2005 the number of Flight problems complaints increased by more than 2 percent.

A．only a

B．only b

C．a and b

D．a and c

From the passage we can know that _______ .

A．customers are not satisfied with CBC

B．sometimes CBC sells more tickets than its plane’s fixed seats

C．CBC has more than twenty planes which fly to all the capital cities of the world

D．customers can only buy tickets with cash