题目

下列说法正确的是：(    ) A CO2分子的空间结构是直线形，故CO2分子是非极性分子。 B  分子CO和N2的原子总数相同，价电子总数相等，故性质相同。  C  Na+的电子排布式为1s22s22p63s1 D 在元素周期表中，s区，d区和ds区的元素都是金属 答案：A阅读下面材料，从所给的五个选项中，选择正确的选项填空，使短文通顺、内容完整。When America was young, the city of Washington, D.C. had been built.   1  .Trees were cut down and the Great Capitol(美国国会大厦) was built. A house was built. The President of the United States would live in this house.   2 At that time there was a park near the President’s house.   3    Today in that same park there are no horses or cows, sheep or pigs.     4 This is a city of many monuments(纪念碑). The highest of all is the George Washington Monument. This monument helps all of us remember George Washington, the first President of the United States. Inside the monument is an elevator. People from all over the country ride in the elevator to the top. Inside the monument are many steps.  5 .When they get to the top, they see the United States Capitol building with its white dome(圆顶) and many monuments. They look over this beautiful city, Washington, D.C.—the capital of the United States.A. People may climb these steps to the tops.B. And people let their horses and cows, sheep and pigs eat grass in the park.C. It is now called the White House.D. It was built in a forest, near two beautiful rivers.E. It is a beautiful park for all people to see.F. It’s near the river.