题目

There was once an old wise man living on the top of a mountain. Whenever the villagers had a problem, they would climb up the mountain and ask the old man for advice. One day a young man arrived. “Wise man,” he asked, “What makes a man truly great?” The old man said, “Do you sincerely want to know?” “Yes, yes!” the young man replied. “Well,” the wise old man said to him, “Let me tell you in the form of a story.” There was once a Greek man who suffered from a deadly disease. Knowing that he would die soon, he was the first to join the army when his country was i 在反应3H2＋N22NH3中，经一段时间后，氨的浓度增加了0.6 mol/L，在此时间内用H2表示的平均反应速率为0.45 mol/(L.s)，则反应所经过的时间为 [　　] A． 0.44 s B． 1 s C． 0.33 s D． 2 s