Washington, April 4----- The United States has more than 90 million families for the first time, but each contains fewer people on average than ever, the Census Bureau(统计局) reported today.
The 90,031,000 families in the United States averaged 2.64 members each as of last July 1.“The reason is, in effect, changes in the age structure,” explained Campbell Gibson, a population researcher for the bureau. Most Americans born in the great explosion of births are now in their 20’s and 30’s when they most likely to set up families, he said.
The fact that many are doing so increased the number of families from 80.4 million in 1980 t0 88.8 million in 1986 and past the 90 million mark last summer.
At the same time, the average number of people per family dropped from 2.75 in 1985 to 2.65 in 1986 and then to 2.64, Mr Gibson said.
By comparison, the 1970 Census found the average family contained 3.14 people. Families averaged more than four people in 1939 and more than five in 1880.
The growing number of ever---- smaller families is still going on, but Mr Gibson pointed out that family growth was not the same as population increase in the 1970’s.
The same age factors that are increasing the number of families also happened then, but in the 1970’s the proportion(比例) of families in each age group was also growing.
That hasn’t continued in the 1980’s for a number of possible reasons, Mr Gibson said. For example, in the 1980’s more young people have chosen to remain home with their parents instead of setting up housekeeping on their own, as many did in the 1970’s.
This could be caused by the increasing cost of housing, he said. Delays in marriage while young people go to work and school, have also been widely reported as a factor, but it was not the only factor for the family changes.
The smaller figure of families reported here is _________.

A．1980

B．80,400,000

C．2.64

D．90 million

What’s the reporter’s attitude towards the present situation?
A. People should get married at later age.

2. The average number of family members should be 2.64.
3. It’s not clear in the report.
4. Young people should set up housekeeping on their own, as many did in the 1970’s.

From the last paragraph we may infer that________.
A. delay in marriage will not help the number of the families

2. delay in marriage is the major factor of the family changes
3. the writer felt sorry that many young people now delay their marriages
4. there must be some other factors which have led to the slower growth in the 1980’s

The underlined word “factor” in the passage means_________.

A．reason	B．something that proves be true
C．advantage	D．something that helps to bring about a result