My mother always told me, "You should explore your own country before stepping out into the world." However, it seems like a tough mission to travel all across its expansive surfaces. But luckily for me, Via Rail Canada offered youths between the ages of 18 and 25 the chance to ride the train across Canada for the month of July. The ticket was a bargain $150. My best friends Trevor, Joel and Jeremy and I immediately jumped at the opportunity and secured four tickets on the great Canadian railroad.

For a group of 20-year-olds, this was like the first flight of young birds from the nest. When we approached the train station in the morning, our 22-day adventure from Sudbury to Vancouver was to begin. Eyes baggy from lack of sleep, we jumped on board as if it was the train to Hogwarts in Harry Potter. Although the thought of three full days on those tracks covering close to 3, 000 kilometres crushed our spirits a little, what happened next caught us by surprise.

The three days on board turned into a summer camp on rails. At night, we would climb up the glass-domed train car, which gave us a scenic view of the starry night sky, untouched by the harmful light pollution. Before we knew it, the warm sun rays beating down on our faces woke us up for another day on the rails. To my surprise, a sea of golden grain fields dominated the landscape-we were in the Canadian Prairies.

Another day slipped away and we set up for another night in the dome. And this time we were greeted by night sky painted by a fantastic thunderstorm. Lightning was striking at an incredible rate. The spectacular and memorable light show left everyone in the glass bubble in complete disbelief.

Arriving in the Rocky Mountains was one of the most surreal (离奇的) experiences of my life. Before the train adventure, if I could have skipped the travel and arrived at the destination, I would have. That is no longer true. I've learned that the journey can be more enjoyable than the destination.

Measles(麻疹)，which once killed 1450 children each year and disabled even more , was nearly wiped out in the United States 14 years ago by the universal use of the MMR vaccine(疫苗). But the disease is making a comeback, caused by a growing anti-vaccine movement and misinformation that is spreading quickly. Already this year, 115 measles cases have been reported in the USA, compared with 189 for all of last year.

The numbers might sound small, but they are the leading edge of a dangerous trend. When vaccination rates are very high, as they still are in the nation as a whole, everyone is protected. This is called "herd immunity", which protects the people who get hurt easily, including those who can't be vaccinated for medical reasons, babies too young to get vaccinated and people on whom the vaccine doesn't work.

But herd immunity works only when nearly the whole herd joins in. When some refuse vaccination and seek a free ride, immunity breaks down and everyone is in even bigger danger.

That's exactly what is happening in small neighborhoods around the country from Orange County, California, where 22 measles cases were reported this month, to Brooklyn, N.Y., where a 17-year-old caused an outbreak last year.

The resistance to vaccine has continued for decades, and it is driven by a real but very small risk. Those who re- fuse to take that risk selfishly make others suffer.

Making things worse are state laws that make it too easy to opt out(决定不参加)of what are supposed to be required vaccines for all children entering kindergarten. Seventeen states allow parents to get an exemption (豁免), sometimes just by signing a paper saying they personally object to a vaccine.

Now, several states are moving to tighten laws by adding new regulations for opting out. But no one does enough to limit exemptions.

Parents ought to be able to opt out only for limited medical or religious reasons. But personal opinions? Not good enough. Everyone enjoys the life-saving benefits vaccines provide, but they'll exist only as long as everyone shares in the risks.        

As we grow up, it becomes natural for people around us to lose contact with the hobbies that once were dominant in their lives. While it's painful to accept this, the new reality becomes normal for most of us as we face new academic, adult and job responsibilities.

I've been dancing since I was four and I plan to continue dancing in college. However, I've always feared that dancing will affect my study and eventually become a brilliant memory of my childhood. After learning about Sommer Gentry's story, I had an answer.

Sommer Gentry, previously a professor of mathematics at the United States Naval Academy and a coach at the Naval Academy's Swing Dance Club, is currently a teacher at NYU Grossman School of Medicine. Gentry and her husband also started a swing dance community to introduce non-dancers to swing dance.

Through teaching, Gentry was inspired to view dancing from an engineering point of view. She said, "I realized it is an engineering question: how do you dance well with someone? It'd be great to give people mathematical and engineering proofs that they have to dance the way I say. " Gentry investigated the complex haptic (触觉的) communication behind the moves in swing dance and showed that two persons could move in coordination (协调) with pure haptic communication, She entered an exciting area of research which is about engineering, psychology and human motor control.

It's incredibly inspiring that Gentry was able to intertwine her academic work with her passion for dancing. Gentry said, "It means that even when I'm dancing outside, I'm thinking about my research project. "

Gentry found that digging into her academic interest does not mean letting go of her other non-academic ones. Instead, she found a way to include both in her professional life. Just like me, Gentry is a mathematician and dancer, thus, her story resonates (引起共鸣) strongly with me, and I want to be like her in the future.