Humans are social animals，and most of us treasure our relationships with family and friends.A research suggests that relationships can keep us healthier.And a new study finds those social connections may also help us live longer.
This new study combined a large number of previous studies and concluded that a lack of social interactions may lead to smoking，obesity，and alcoholism(酗酒) as a risk factor for death.
Professor Julianne HoltLunstad，one of the authors of the study，pointed out several ways relationships can affect our health.They can help us deal with stress.They can help us keep healthy habits like eating well，exercising or seeing a doctor.And_there’s_increasing_research_that_show_a_direct_but_poorlyunderstood_link_between_relationships_and_physiological_processes_in_the_body.
“So for instance，our relationships have been linked to lower blood pressure，better immune(免疫的) function.”said HoltLunstad.“And so our relationships can influence our health in a variety of ways that are all very important.”
Even though HoltLunstad and her colleagues looked at almost 150 different scientific studies，most of them didn’t assess(评估) the quality of the relationships.
“And certainly relationship quality matters，and not all relationships are entirely positive，”she said.“And so it’s possible that the effects that we have reported may be conservative(保守的)，and that the odds(几率) of survival associated with highquality relationships may actually be large.”
She said her research suggests that policy makers need to consider relationships as a health issue.So just as nosmoking zones have expanded over the years，she suggests that city planners，for example，should consider whether their decisions might promote the development of personal relationships.
According to the text，a lack of social interaction may lead to ________．

A．serious illness

B．mental problems

C．drinking too much wine

D．worrying too many things

What does the underlined sentence mean in the third paragraph?

A．Relationships have nothing to do with physiological processes.

B．People have known the indirect link between relationships and physiological processes.

C．The link between relationships and physiological processes has not been studied.

D．People haven’t fully understood the link between relationships and physiological processes.

What does the author want to tell us in the last paragraph?

A．The government should improve people’s health.

B．Policy makers should promote social interations.

C．The government should encourage people not to smoke.

D．Policy makers need to have good social communication.

What would be the best title for the text?

A．A health issue

B．Social interactions

C．How to live longer

D．Social interactions help you live longer