Richard found a job in a big office after he finished college. He liked to use his 1 and was good at his job. So he was often paid more than (得到的报酬多于) his workmates and he worked 2 . But something was wrong with the young man a month ago. He couldn't fall 3 at night. So he was always 4 in the daytime and often made mistakes. He had to go to a hospital. The doctor 5and told him to buy some sleeping pills. He took them 6 he went to bed. Soon after that he went to sleep. Richard 7 in the morning. He had a look at the clock on the wall. It was a quarter to seven. He got up and went to work after 8 . As soon as he went into the office, he said to the head of the office, "Good morning, Mr Clarke! I've 9 had a good sleep like last night's and I'm feeling much better now!" "Skunk (混蛋)!" the head 10 loudly. "We've looked for you for two days! I wanted you to do something important, but it's too late now!"
xC（g）＋2D（g），经5min后，测得D的浓度为0.5mol/L，