Dogs greet other dogs’ noses first, sniffing (嗅) each other from head to tail. People are not so open about the process of sniffing, but smell is important in human relations, too. There is also evidence that humans can infer relationship and emotional states and even discover disease through smell.

Now, Inbal Ravreby, Kobi Snitz and Noam Sobel of the Weizmann Institute of Science have gone a step further. As they report in Science Advances, the three researchers started their first experiment by testing the smells of 20 pairs of familiar and same-sex friends. They employed an electronic nose (e-nose) and two groups of human “smellers”.

The e-nose used a set of gas sensors to assess T-shirts worn by participants. One group of human smellers were given pairs of these shirts and asked to rate how similar they smelt. Those in the other group were asked to rate the smells of individual T-shirts on five dimensions (维度): pleasantness, intensity, attractiveness, competence and warmth.   Both approaches produced the same result. The T-shirts of friends smelt more similar to each other than did the T-shirts of strangers.

Does friendship cause similarity of smell, or does similarity of smell cause friendship? The three researchers investigated whether there were positive interactions between strangers by using the e-nose measurement. They collected the smells of another 17 volunteers with e-nose, and then asked the participants to play a mirroring game.

That game involved silently mirroring another individual’s hand movements, Participants were paired up by chance and their reactions were recorded. After each interaction, they demonstrated how close they felt to their fellow gamer by overlapping two circles (one representing themselves, the other their partner). The more similar the two electronic smell signatures were, the greater the overlap. Participants also rated the quality of their interaction in the game along 12 dimensions of feelings that define friendship, Similar smells were consistent with positive ratings for nine of these dimensions. However, two participants smelling alike did not mean they were any more accurate at the mirroring game than others.

Why smell might play a role in forming friendships remains obscure. Other qualities related to being friends, including age, appearance, and education, are either immediately obvious or rapidly become so. But while some individuals have strong body smell, many do not. It is present. But it is subliminal (潜意识的). Dr Ravreby guesses that there may be “an evolutionary advantage in having friends that are genetically similar to us”. Body smell is known to be linked with genetic make-up. Smelling similar to others may thus allow subliminal inferences about genetic similarity to be drawn.

You’ll make new friends in each stage of your life. Some of them will come and go, while others will last for the rest of your life. 【小题1】

There are many benefits of having strong friendships. According to experts, many people regret not keeping friendships going and end up living a life with no close friends or even enduring mental and physical sufferings. 【小题2】 People who have healthy friendships tend to enjoy life more and may even live longer.

【小题3】 There are a lot of ways to make new friends that can stay with you for the rest of your life. Look for people who share things with you. If you have kids, join a mom’s group, or sign your child up for classes where you’ll naturally meet other parents. 【小题4】 You share your career and will have a lot to talk about while also having built-in opportunities to spend time with each other.

Sometimes it’s a good idea to let a friendship go, even if you’ve been friends for a long time. If one party isn’t making an effort to keep things going, it can lead to feelings of hurt and betrayal, and it might be time to let things cool off and pursue other friendships. 【小题5】 Besides, it can encourage you to focus on the partnerships that are healthy and where both of you are committed to keeping it going for your entire life.

On Punctuality

A punctual（守时的）man is in the habit of doing everything at the proper time and is never late for an appointment.

The unpunctual man，on the other hand，never does what he has to do at the proper time. 【小题1】There is an old saying "Time flies never to be recalled." This is very true. 【小题2】 Time is more valuable than material things. In fact，time is life itself，and the unpunctual man is forever wasting and mismanaging his own valuable assets（资产）as well as others'. The unpunctual man is always complaining that he finds no time to answer letters，or to return calls，or to keep appointments promptly（准时地）. 【小题3】He knows that he can't get through his large amount of work unless he faithfully keeps every appointment promptly and deals with every piece of work when it has to be attended to.

【小题4】If a person is invited to a dinner and arrives later than expected，he keeps all the other guests and the host waiting. This is great disrespect.

【小题5】Imagine how it would be if the people who are entrusted with important tasks fail to be at their proper place at the appointed time. A man who is known to be habitually unpunctual is never trusted by his friends or his fellow men. And the unpunctual man is a source of annoyance both to others and to himself.