中国戏曲的最早雏形是什么？

市场定位战略主要有( )。

A．产品差别化战略

B．服务差别化战略

C．销售差别化战略

D．品牌差别化战略

E．形象差异化战略

导游员的旅行知识有( )等，掌握这些知识就能少出差错，事半功倍。

A．交通知识

B．通讯知识

C．货币保险知识

D．卫生防预知识

E．旅游业知识

图中所示为氢原子能级图，可见光的光子能量范围约为1.62eV~3.11eV。

下列说法正确的是                                                       

A．大量处在n>3的高能级的氢原子向n=3能级跃迁时，发出的光有一部分是可见光

B．大量处在n=3的氢原子向n=2能级跃迁时，发出的光是紫外线

C．大量处在n=3能级的氢原子向n=1能级跃迁时，发出的光都应具有显著的热效应

D．处在n=3能级的氢原子吸收任意频率的紫外线光子都能发生电离

完成句子

阅读下列各小题,根据每句后的汉语提示,用句末括号内的英语单词完成句子.

1. The boy ____________________ reading a novel that he forgot there was a large amount of

    homework remaining unfinished. (lose)

这个男孩如此入迷地看着小说,以至于都忘了还有一大堆作业没写完.

2. If all nations ____________________their energy supply sources to reduce waste a little earlier,

    things would be much better now. (seek)

如果所有的国家早一些通过寻求改变能源供应的来源来减少浪费的话,现在一切都会好很多.

3. It is not who is right but what is right ______________. (importance)

重要的不是谁是对的,而是什么是对的.4. Nothing gave the mother more pleasure than ____________________ to be useful citizens of the country. (bring)

没有什么比看见自己的孩子被培养成对祖国有用的人才更让她高兴的了.

 5. The combined working group will look into the train rearend collision(追尾事故), ____________________ the cause of accident officially and punishing some responsible persons concerned. (account)

联合工作小组将会调查火车追尾事故,来正式说明事故原因,并惩罚相关的负责人员.

6. They were about to get down the hill ________________heavily. (begin)

他们正要下山,这时天突然开始下起了大雨.

7. They urged him to go on with his story, so he had to stop ____________________the delicious

    food on the table. (stare)

他们催促他继续(讲)他的故事,因此他不得不停止盯着桌上美味的食物.

8. The rain was heavy but, ____________________, our fields were not flooded. (contrary)

尽管雨下得很大,不过和我们的担忧相反,我们的地并没有被淹没.

9. Not being able to come up with a solution to his being penniless, he had to earn his living ________________________. (work)

实在是想不出什么方法能够解决他的贫困问题,他不得不靠做服务生谋生.

10. The teacher asked ____________________the present situation, but there was really no quick

      answer to it. (do)

老师问我打算如何处理目前的状况,但是这个问题真的很难用一两句话来回答.

在误差分析中，样本平均值与总体平均值误差越大，则准确度越低。( )