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问题 单项选择题

某分部工程有两个施工过程，分为4 个施工段组织流水施工，流水节拍分别为3、4、4、5 天和4、3、4、5 天，则流水步距为（ ）天。

A．3

B．4

C．5

D．6

答案

参考答案：C

填空题

Dear Nancy
I am happy to tell you my school and my life. Every day my father drives me to school. My school is very big and beautiful. I like my school very much. The desks and chairs are new. There are lots of pictures on the walls. You can also see some flowers on the teachers’ desk. We clean the classroom every day.
I don’t go to school on Saturday and Sunday. I get up at six on Saturday. I play basketball with my father in the park near my home for half an hour. Then I eat my breakfast. I help my mother water the trees and flowers in the garden. At eight I begin to do my homework. My parents and I have lunch in the KFC. In the afternoon. I have Art lessons. Sometimes I play computer games or chat with my friends on the Internet in the evening.
I like my weekend very much.
Yours
Li Hua
Who is the letter from?
It tells about Li Hua’s school and     1   .
2     does Lihua go to school every day?
He goes to school by     3   with his father every day.
What is his school like?
It’s big and beautiful.
What does he usually do at weekend?
He often     4  basketball with his father and helps his mother water the trees and flowers in the garden.
When does he do his homework on Saturday?
He does his homework in the   5  .
How can he chat with his friends?
He can chat with his friends on the Internet.
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实验题

为了测量玩具遥控汽车的额定功率，某学习小组用天平测出小车质量为0.5 kg，小车的最大速度由打点计时器打出的纸带来测量(如图所示)。主要实验步骤有：

A. 给小车尾部系一条长纸带并让纸带穿过打点计时器；

B. 接通打点计时器电源(电源频率50 Hz)，使小车以额定功率沿水平地面直线加速到最大速度，继续运行一段时间后关闭小车发动机，使其沿地面直线向前滑行直至停止；

C. 学习小组分析后选择了认为符合要求的一段纸带，从某点开始每5个连续点标为一个记数点，并将表示每两个相邻记数点间距离的字母和测量数据在纸带上做了记录。（所有结果均保留2位有效数字）

① 相邻两记数点间的时间间隔T = ______s，由纸带知遥控汽车的最大速度为=_________m/s；

② 实验小组在计算关闭发动机后的遥控汽车滑行过程的加速度时，选择了纸带上后5段数据，经过分析又舍掉了一段不合理数据。请你判断哪段数据不合理_________ (用字母表示)，舍掉了不合理数据后加速度的计算表达式为="_________" (请用时间间隔T及纸带上表示记数点间距离的字母表示)，计算出的加速度大小为______m/s2；

③ 遥控汽车滑行过程的阻力大小为=_________N，其额定功率=_________W。
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