完形填空
One day，a teacher entered the classroom and told the students about a test. After hearing，all students were seated and waited for the test to1. Now, the teacher gave the test papers to all students and put the text face down at the desk. When he finished handing out the test to all students, he asked2 to turn the test pages and begin.
Students were surprised to see that there was not a 3 but just a black dot in the center of the page. The teacher noticed the students' face expression and told them, “I want you to write about 4you see there.”
The students were still5but got started with the test. At the end of the class, the teacher took all answer sheets and started reading each answer from each sheet in front of all students. All of them described about the black dot and tried to explain its position etc. After the teacher finished reading, the whole class was6.
Then professor began to explain, “Don't worry, I am not going to give you 7 for this but I just want you to think about something. Here everyone focused on the black dot and wrote about it,8no one wrote about the white paper, the 9 is with our lives. The white paper stands for our whole life and the black spot stands for10in our life.
Our life is a gift given to us by God,11love and care, and we always have reasons to celebrate –our friends around us, the job that can 12us our living, the miracles we see every day.
Still we just13 day to day problems like health problems, lack of money, problems in relationships etc. but we never see that these problems are very small compared to14 we have in our lives.”
So we should try to take eyes off our problems and15each moment that life gives us. Be happy and live life positively.
2SO3，达到平衡时，n(SO2)∶n(O2)∶n(SO3)＝2∶3∶4。缩小体积，反应再次达到平衡时，n(O2)＝0.8 mol，n(SO3)＝1.4 mol，此时SO2的物质的量应是( )