Which of the following is a bad habit of the executive passengers that frustrates the airlines?(  )

• A、They do not book their seats in advance.
• B、They do not sit on the seats they are supposed to take.
• C、They do not travel on the flight they have booked.
• D、They do not pay in advance for the seats they book.

第六部分:完形补文(第41~50题,每题1.5分,共15分)

下面的短文有10处空白，每处空白后的括号内有一个词,请根据短文内容将其正确的形式填入文中,以恢复文章原貌。

The Family

The structure of a family takes different forms around the world and even in the same society. The family's form changes as it adapts to   41   (change) social and economic influences. Until recently ,the most common form in North America was the nuclear family,   42   (consist) of a married couple with their minor children, The nuclear family is an   43   ( depend) unit. It must be prepared to fend for it self. Individual family members   45   (strong) depend on one. another. There is little help from outside the family in emergencies. Elderly   45   ( relative) of a nuclear family are cared for only if. it is possible For the family to do s0. In North America,the   46   ( elder) often do not live with the family;they live in   47   ( retire) communities and nursing homes.

There are many parallels. between the nuclear family in,   48   ( industry) societies, such as North America,and of family in societies such as that of the Inuits, who live in harsh environments. The nuclear family structures well   49   ( adapt) to a life of mobility. In harsh conditions, mobility allows the family to hunt for food. For North Americans,the hunt for jobs and   50   ( improve) social status also requires mobility.

According to the passage, in operating airlines it is essential to     .(  )

• A、keep in mind the need. of the executives only
• B、satisfy the need of the low fare passengers at the expense of the executives
• C、try to attract as many passengers as possible by reducing fares
• D、cater to the need of passengers setting at both ends of the jets