4 . Our fascination with Mars has never stopped. However, in the early days of space exploration, visits were restricted to “fly-bys”, such as those by Mariner Space Probes, by means of which craft would simply pass the planet, taking pictures and collecting data as they went. The Viking “orbiters” were next, and later craft in the Viking series, known as “Landers”, began to study the surface, equipped with instruments which continued to collect data about the environment until they stopped working.

The more recent “Rovers” move around the planet’s surface as they gather information. Current proposals include missions to study geographic features, climate, and soil components, in order to determine, among other things, whether the planet can ever have supported carbon-based life forms. Scientists now believe that at some stage the planet cooled dramatically, resulting in the near-loss of its atmosphere and, thanks to the wearing away of some surface features mineral deposits and other factors, it is also believed that liquid water once flowed here.

One of the most famous craft is “Phoenix”, which landed in November 2008. Its mission was to obtain samples from beneath the surface by digging into the arctic ice while its camera provided geological data and other equipment scanned the atmosphere, measuring temperature and pressure in an attempt to discover whether the chemicals necessary for life might exist beneath the surface. The craft was expected to send back data for three months, but managed to hold out for further two. An especially important part of the project was the need to keep absolute cleanliness of the equipment in order to ensure that any organic material collected was not contaminated by microbes(微生物).

In the future manned landings may probably come true-and though it may seem an extremely difficult undertaking, plans have already been discussed for the “terraforming(行星地球化)”of the planet, giving it an atmosphere, oceans and other elements similar to earth, with, the possibility of human settlement.

5 . Connecting with people has become so much easier with advancing technology. Tasks that once required a postage stamp or carrier pigeon are now as simple as tapping a name or even a face on your screen, and you’re connected. But also easier is unconsciously getting caught up in a dilemma by violating certain new rules for communicating. A big one for some: Don’t call until you’ve texted to confirm it’s OK to call. But that’s just the beginning.

“I’m usually pretty mild and not much bothers me,” said Mark Angielle, a 29-year-old office manager from White Plains, New York. But the one thing that he hates more than anything else in life is the terrible one-word message — “K.” “At the very least reply with, Got it.” he said “At least give me a few words here. You’re not that busy.”

There are hundreds, perhaps even thousands, of others who have taken Lo social media to express their distaste for people who don’t follow the unwritten rules of digital communication.

“These rules are simply a new display of a phenomenon we’ve seen in the past,” said James Ivory, professor of communication a Virginia Tech. In the same way that generations and small groups of friends have their own slang and customs, internet culture has given birth to technology-dependent beings that have their own unique set of routine.

But not everyone gets the point. Unlike language, digital communication can be filled with ambiguous clues (线索、迹象) that the person on the other end of the call, text or email may or may not easily understand.

“As soon as people aren’t talking face to face, the first thing that gets lost is some of the richness of the body language,” Ivory said, “People immediately fill that gap by using emoji (表情符号) to sum up a feeling in seconds.

“There's great potential for danger,” Ivory warned. “What's considered polite in one form might be inappropriate or rude in another occasion.”

6 . When I was in fourth grade, I worked part-time as a paperboy. Mrs. Stanley was one of my customers. She’d watch me coming down her street, and by the time I’d biked up to her doorstep, there’d be a cold drink waiting. I’d sit and drink while she talked.

Mrs. Stanley talked mostly about her dead husband, “Mr. Stanley and I went shopping this morning.” she’d say. The first time she said that, soda(汽水) went up my nose.

I told my father how Mrs. Stanley talked as if Mr. Stanley were still alive. Dad said she was probably lonely, and that I ought to sit and listen and nod my head and smile, and maybe she’d work it out of her system. So that’s what I did, and it turned out Dad was right. After a while she seemed content to leave her husband over at the cemetery(墓地).

I finally quit delivering newspapers and didn’t see Mrs. Stanley for several years. Then we crossed paths at a church fund-raiser(募捐活动). She was spooning mashed potatoes and looking happy. Four years before, she’d had to offer her paperboy a drink to have someone to talk with. Now she had friends. Her husband was gone, but life went on.

I live in the city now, and my paperboy is a lady named Edna with three kids. She asks me how I’m doing. When I don’t say “fine”, she sticks around to hear my problems. She’s lived in the city most of her life, but she knows about community. Community isn’t so much a place as it is a state of mind. You find it whenever people ask how you’re doing because they care, and not because they’re getting paid to do so. Sometimes it’s good to just smile, nod your head and listen.

7 . The Canadian red and white maple leaf (枫叶) flag is officially called the National Flag of Canada. The Canadian flag shows a stylized red maple leaf with 11 points on a white background, with red borders down each side. The Canadian flag is twice as long as it is wide. The white square containing the red maple leaf is the same width as the flag.

The red and the white used in the National Flag of Canada were proclaimed the official colors of Canada in 1921 by King George Ⅴ. Although the maple leaf did not have its official status as a symbol of Canada until the announcement (宣告) of the national flag in 1965, it had historically been used as a Canadian symbol, and was used in 1860 in decorations for the visit of the Prince of Wales to Canada. The 11 points on the maple leaf have no special significance.

In the early days, the Royal Union Flag, or the Union Jack, was still flown in British North America. In 1925 and again in 1946, the Canadian Prime Minister Mackenzie King tried to get a national flag of Canada adopted, but failed. In 1964, Prime Minister Lester Pearson appointed a 15-member, all-party committee to come up with a design for a new flag. The committee was given six weeks to complete its task.

The committee studied 2,000 submitted (提交的) designs as well as 3,900 that had been gathered as a result of the 1946 committee’s study. Those designs with a chance of being accepted were given to the full committee for further study.

The suggestion of a red and white single maple leaf design for the Canadian flag came from George Stanley, a professor at the Royal Military College. After a heated discussion, they finally decided on his suggestion.

9 . There are times when people are so tired that they fall asleep almost anywhere. We can see there is a lot of sleeping on the bus or train on the ______ home from work in the evenings. A man will be _______ the newspaper, and seconds later it     _____as if he is trying to ______ it.Or he will fall asleep on the shoulder of the stranger ______ next to   him. ______ place where unplanned short sleep ______ is in the lecture hall where a student will start snoring(打鼾)so ______ that the professor has to ask another student to ______ the sleeper awake. A more embarrassing(尴尬)situation occurs when a student starts falling into sleep and the ______ of the head pushes the arm off the ______ ,and the movement carries the ______ of the body along. The student wakes up on the floor with no ______ of getting there. The worst time to fall asleep is when ______ . Police reports are full of ______ that occur when people fall into sleep and go ______ the road. If the drivers are ______ , they are not seriously hurt. One woman's car, _______ , went into the river. She woke up in four feet of ______ and thought it was raining. When people are really ______ , nothing will stop them from falling asleep-no matter where they are.

Two years before, I traveled to Brazil and I rented for a car. Unfortunate, I had an accident and hit another car, and I needed to stay in a hospital for at least two week. I called my parents, so I did not tell them what had happened. I knew that they will be worried about myself because I was so farther away, and that my mother would not sleep if she knew. Therefore, I told them interested stories and how I was enjoying Brazil. As a result, nobody knew truth. I still think that it was the right thing to do.