阅读下面短文,理解其大意,然后从各题所给的四个选项中选出最佳选项。
One day a professor entered the classroom and told the students about a surprise test. Now the professor gave the test papers to all students with text facing down at the desk. After he 1 the test to all students, he asked —them to turn the test pages and begin.
Students were 2 to see that there was not a question but just a black dot(小圆点)in the center of the page. The professor 3 the students' face expressions and told them," I want you to write about what you see there."
The students were 4 surprised but got started with the test. At the end of the class, the professor took all answer papers and started reading each 5 from each paper. All of them 6 about the black dot and tried to explain its position(位置). After the professor finished reading, the whole class was 7 .
8 , the professor explained, "Don't worry. I'm not going to give you 9 for this test, but I just want you to think about something. Here everyone paid attention to the black dot and wrote about it 10 no one wrote about the white paper, the same is with our lives. The white paper represents our whole life and the black spot represents 11 in our life.
Our life is a gift given to us 12 God, with love and care, and we always have reasons to celebrate-our friends around us, the joy 13 provides us our livelihood, the happiness in our families. Still we only care about problems like health problems, study problems, problems in relationships, but we 14 see that these problems are very small compared everything we have in our lives”
So we should try to take eyes off our problems and enjoy each nice moment that life gives 15. Just smile, and life will smile to us!