题目内容：

A Samoan airline says that it is the world’s first carrier to charge passengers by their weight. Samoa Air, which opened in 2012, asks passengers to give their personal weight during booking, which is then charged according to the length of a flight. The customers will also be weighed just before they board the plane.

"It is believed that all people throughout the world are the same size," Samoa Air CEO Chris Langton said. "Airplanes always run on weight, not seats."

"There is no doubt in my mind that this is the concept of the future. This is the fairest way of your travelling with your family or yourself."

Though the airline introduced the plan last November, it caught people's attention last week when the carrier began international flights to neighboring American Samoa.

Almost at the same time, a Norwegian economist, Bharat Bhatta, published a report suggesting that airlines should charge obese passengers more.

The Pacific Islands contain some of the world’s most common countries for obesity, many ranking in the top 10, according to the World Health Organization (WHO). Samoa is ranked number four, with 59.6 percent of the population considered obese, said the most recent WHO report.

According to Samoa Air's latest schedule, the airline charges up to $0.57 per kg for flights in Samoa and $1.03 per kg for its only international flight to American Samoa, around 250 miles.

Children under 12 are charged 75 percent of the adult rate, with fares also based on weight. Any overweight baggage is calculated at the same rate as the passenger's personal weight.

The plan could actually prove cheaper in some cases, such as for families travelling with small children, and Langton said customer reaction has mainly been "amazingly positive".

The idea of charging passengers by weight has been hotly discussed before, and in the US some airlines require those who do not fit into a seat comfortably to buy a second seat.

1.What does the underlined word "this" in Paragraph 3 refer to?

A. Airlines should charge passengers by flight length.

B. All people throughout the world are the same size.

C. It is unfair to weigh passengers at the airport.

D. Airplanes always run on weight, not seats.

2.In Bharat Bhatta’s eyes, Samoa Air's plan might be _______.

A. funny    B. acceptable

C. strange    D. disappointing

3.A 100 kg adult flying to American Samoa would be charged _______.

A. $57    B. $75

C. $103    D. $125

4.What does the text mainly tell us?

A. 59.6% of Samoans are considered obese.

B. Samoa Air introduces pay-by-weight pricing.

C. Airlines should charge obese passengers more.

D. Baggage must be calculated as passengers’ weight.