Everyone in our village likes Harry beca

与NH

+

4

含有相同电子数的微粒是（　　）

A．Na⁺

B．F^-

C．OH^-

D．H₂O

Residents ________ not to go out alone or to take part in any groups during the period of recent terrorist activities.

A．were always being warned

B．are always warning

C．always warned

D．had always been warned

More patients _____ in hospital this year than last year.

A. treated B. have treated C. had been treated D. have been treated

“灯官”的就职演说：

 在集体中，每个同学都承担了一份责任，有的同学负责板报，有的同学做了生活委员，老师安排我负责管理电灯，根据情况开灯，并且在不需要时及时关灯。有些同学看不起我这个“灯官”，但是我认为这个工作很重要，不仅可以保护同学们的眼睛，还能节约能源。最重要的是我也为集体贡献了自己的一份力量。

对于这份就职演说，你有什么感想？

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信息储存的方法主要是根据信息提取的频率和数量，建立一套（）。