关于横结肠的描述，哪项是错误的？（）A.起于结肠右曲 B.主要由中结肠动脉所供应 C

单词拼写。

根据句子的意思和所给的首字母写出单词.

1. A lot of facts show that China is not only one of the cradles(摇篮) of human c________, but also

    the cradles of man himself.

2. Many r           from different provinces were present at the Fifth Session of the 11th National People's

   Congress.  

3. Zhang Yishan and Yang Zi are both junior school students, but that's not stopping them from

    becoming c________ in China because of their performance in the TV show Home with kids.

4. The painting proved to be an unknown m_________ by Leonardo da Vinci.

5. The two buses went in o            directions - one went south and the other went north.

我国《道路交通安全法》规定：严禁酒后驾车！参照《车辆驾驶人员呼气酒精含量阈值与检验标准(GB19522)》，呼气中酒精浓度大于等于0. 09mg/L就属于酒后驾驶．由此，某实践活动小组的同学就“呼气中酒精浓度是否超标”展开探究活动，小组同学通过资料查询，知道氧化锡具有气敏特性，当周围气体中酒精浓度增加，其电阻值就降低．他们到电子器材商店购得某型号氧化锡检测电阻Rx，其阻值与周围气体中酒精浓度的关系图像如图所示．同学们按如下器材和方法展开实验探究。器材元件：6V电源、开关S、氧化锡检测电阻Rx、定值电阻Ro、电压表、导线，电路；功能：闭合开关S，检测者呼出气体流经Rx．若电压表读数大于等于1. 5V检测者属于酒后驾车；若电压表读数小于1.5V，则不属于酒后驾车。要求：（1）请用笔划线代替导线完成电路连接；（2）计算出定值电阻Ro的阻值

放火焚烧圆明园是在哪一次侵略战争中发生的[ ]

A．第二次鸦片战争  

B．甲午中日战争  

C．八国联军侵华战争  

D．鸦片战争

某科研项目单次的实验费用达五位数，该科研每次的实验费用至少是[ ]

A．1万元

B．10万元

C．99999元

网络200.105.140.0/20中可分配的主机地址数是______。

A．1022
B．2046
C．4094
D．8192