The Internet has become part of teenage life. There’s a report on 3,375 students aged from 10 to 18 in seven Chinese cities. It says that 38% of them believe they use the Internet often. While most of them get useful information and use the Internet to help in their studies, some are not using it in a good way. Many are playing online games too much. A few even visit Web sites they should not look at. Bad things can happen if young people spend too much time on the Internet.
   In order to help young people use the Internet in a good way, a textbook on good Internet behavior has started to be used in some Shanghai middle schools this term. It uses real examples to teach students all about good ways of using the Internet. Some students also make online friends. But if you are meeting a friend offline, let your parents know.
   Teachers and parents all think the book is a very good idea. It will teach students how to be a good person in the online world. It will be a guide for teens using the Internet and keep students away from bad sites.

高速公路电子收费系统(ETC)涉及了无线电通信、计算机、自动控制等多个知识领域。车辆在高速路出口驶入ETC车道时，系统对车辆身份进行识别，并从车辆IC卡中扣除相应通行费后，电动栏杆自动抬起，车辆即可通行。下列说法不正确的是（   ）

东北是我国重要的水稻产区。据此回答下列各题。
【小题1】东北大米因质量优而广受欢迎，与其有关的因素有                                              
①东北水稻的生长期长                 ②东北地区气候寒冷，病虫害少 
③东北地区土壤肥沃，化肥使用量相对少 ④东北地区水稻生产机械化水平高

A．①

B．①②

C．①②③

D．①②③④

【小题2】有关东北水稻种植的说法，正确的是                                                                   
①水稻是东北产量最高的粮食作物 
②水稻种植比例由南向北逐渐增加 
③水稻种植已扩展到北纬50°以北的黑龙江沿岸 
④东北水稻种植业的发展方向是规模化、专业化、生态化

Keep ____ (quietly), because the baby is sleeping.