问题
选择题
将a mL NO、b mL NO2混合于同一试管中，将试管口倒插入水中，再通入x mL O2，充分反应后试管内气体可全部消失，则x对a、b的函数关系式f［x(a，b)］是（ ）
A．
B．
C．
D．
答案
答案：C
由4NO2+O2+2H2O====4HNO3和4NO+3O2+2H2O====4HNO3得x=
。
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将a mL NO、b mL NO2混合于同一试管中，将试管口倒插入水中，再通入x mL O2，充分反应后试管内气体可全部消失，则x对a、b的函数关系式f［x(a，b)］是（ ）
A．
B．
C．
D．
答案：C
由4NO2+O2+2H2O====4HNO3和4NO+3O2+2H2O====4HNO3得x=。
| 阅读理解。 | ||
| It was Mother's Day. A man stopped his car at a flower shop to order(订购) some flowers. | ||
| ||
| He bought the little girl her rose and ordered his own mother's flowers. As they were leaving, he offered to drive the girl home. She said, "Yes, please! You can take me to my mother," She brought him to a cemetery(墓地), where she placed the rose on the grave. The man was moved. He returned to the flower shop, picked up the flowers he ordered, and drove two hundred miles to his mother’s house. Today is the day for your mother. Send a flower to your kind and beautiful mother. | ||
| 1. The man went to the shop to ______. | ||
| A. help the girl B. order some flowers C. buy some food | ||
| 2. The man’s mother lived ______ away from him. | ||
| A. 2 kilometres B. 200 kilometres C. 200 miles | ||
3. The girl was crying on the road because ______. | ||
| A. she was hungry B. she couldn’t buy a rose C. she couldn’t find her way home | ||
| 4. After the man bought the girl a rose, they went to together. | ||
| A. the cemetery B. the girl’s home C. his mother’s house | ||
| 5. From the passage we can infer(推断) that ______. | ||
| A. the girl loved flowers very much B. The girl loved her mother very much C. The shopkeeper sent the flowers to the man’s mother |
