— You must be looking forward to your tr...

It was graduation day at the university where I work and a beautiful day quite unlike the first graduation I attended as a young professor．On that cold day years ago, as we watched the students walking into the hall, one of my colleagues turned to me and said, "Graduation will be one of the happiest and one of the saddest time of your life．" At my inquiry, he answered, "Because the students you have gotten to know have to leave．"

As years went by, my previous confusion about my colleague's words no longer existed．When I came across naughty students, I have had to rethink why I chose to be a teacher．It obviously isn't the money．Once a former computer science student of mine called me, asking me if I wanted to have a change．He was working at Nintendo Corporation．His salary was higher than my current one, though I have more education and have worked for over a decade．With my programming skills, he said he could get me hired．I thanked him, but declined his kind offer．

A few days before this current graduation, while working on final grades, I found a note a student had slipped in with her homework．She thanked me for being her teacher and said the things she had learned in my class—not about math, but about life—would be things she would remember long after the math skills had faded away．As I finished reading, I remembered why I had become a teacher．

Now, on this sunny graduation day, as I again observed the sea of blue hats and gowns, I did so with renewed dedication （奉献） and a deeper sense of satisfaction—I will always be grateful that I am a teacher．

1.Hearing his colleague's description of graduation for the first time, the author __________．

2.The computer science student called up the author because he___________．

3.The underlined part “blue hats and gowns” refers to___________．

4.The author wrote this passage to __________．

In 1990 a report was published about what the earth might be like 20 years from then on. The report was a result of a three-year ___36___. according to the report, the picture of the earth in the year 2010 is not a ___37___ one. The world will be more __38___ because the population will continue to grow. The population could be ___39__ 6 300 million, almost 2 150 million more than in 1985. More people would move into cities, especially cities in ___40___ countries. Cities like Cairo and Jakarta probably would ___41___ have 15 million by then.

Food production will ___42___, but not enough to feed all the people. Farmers will grow 90% more food than they did in 1985, __43___ most of the increase would be in countries that ___44___ produce enough food for their people. Little increase is ___45___ in South Asia, Africa and the Middle East. Poor farming ways are ___46___ large areas of crop land, changing farms into deserts. More farmland is ___47___ as cities become larger and more houses are built. ___48___ will get worse as industrial countries burn more coal and oil. Many of the world’s ___49___ could disappear as more and more trees are cut down. Energy will continue to be a serious problem. The experts say their picture of the earth for the year 2010 ___50___. They only carried out the situation that ___51___ today. By changing the situation, by ___52___ the problems, the picture can be changed. There is ___53___ time for the nations of the world to work ___54___ a plan of action. But they warned that ___55___ too long to make decisions would greatly reduce the chances of success.

__________ the experiment right, I tried again and succeeded.

---When shall we meet your cousin at the station?

---His plane took off 2 hours ago, and it _________ arrive at 5pm.

A lot of research and studies have shown that Trench oil, taken out from kitchen waste, ______ the increase of cancers.