第6部分：完形填空（第51～65题，每题1分，共15分）
下面的短文有15处空白，请根据短文内容为每处空白确定1个最佳选项。
Friends May Be Key to Living Longer
Looking for the secret of a long life? Look closely at your friends. New research suggests that having a strong network of friends helps people live longer.
"Older people with better social networks of friends were less likely to (51)
over a 10-year follow-up (随访) period than older people with (52) friends networks，" Lynne C. Giles of Flinders University in Australia told Reuters Health.
But in what may come as a surprising finding to older people (53) rely on their children and other relatives， having a large network of relatives was not associated with longer life， according (54) Giles and her colleagues.
"Of course， that is not to say that social networks (55) children and other relatives are not important in many other ways，" Giles said.
Study after study has shown that elderly people who (56) connected with lots of people tend to live longer lives. (57)， few studies have examined whether different types of relationships - with friends， partners， children and (58) relatives - have different effects on longevity (长寿).
Giles's team set out to examine the relationship between various types of social networks and (59) in a group of almost 1，500 Australians who were at least 70 years (60). Volunteers answered (61) about their social networks and then were followed for 10 years.
The researchers took into account several factors that could have influenced how long a person lived， (62) sex， age， health and smoking status.
What the study showed was (63) older people who reported better social networks of friends were (64) likely to be alive at the end of the study than people with fewer friends.
But relationships with children and other relatives did not have (65) effect on survival in the study.
51 A live B die C work D stay
52 A stronger B larger C newer D poorer
53 A which B whom C those D who
54 A at B to C on D by
55 A by B on C of D in
56 A is B are C was D were
57 A However B Once C Further D Moreover
58 A older B richer C some D other
59 A loneliness B longevity C activity D happiness
60 A big B long C old D ago
61 A doubts B questions C studies D tests
62 A taking B including C accepting D offering
63 A if B when C this D that
64 A less B more C very D most
65 A each B every C an D all