A new term has begun. Teachers are 1 about the fact that new students are not easy to handle. They like to bring cellphones and MP3 players to school. What is2，some students even use cellphones to do with out-of-class matters in class，or sometimes just for fun. Some other students listen to MP3 players when they are having a lesson that they are not interested in.
Are these new students really that3? ’Yes，’ says Delaney Kirk，a professor at Drake University.4she adds it’s not their fault. Instead， the things that they bring into school---cellphones，MP3 players and so on --- and the teachers are to blame. Kirk first began thinking about students’ manners six years ago. ‘I had my first class in which students were sleeping or talking to each other. It seemed that learning well 5 nothing to do with them，’ she says. ’At first，I got worried about this，but then I said to myself， "You’re teaching 6，and you need to  manage this…These students need to know more about manners. It’s time to help them develop some good 7 . They shouldn’t waste time doing nothing when they are young. Sooner or later，they might regret the time they have wasted."’
Kirk also   8 a list of suggestions to help teachers better manage their classes. The following are among her suggestions：
●  Tell students how they will benefit by taking the class. On the first day of class，emphasize its importance9giving some homework that students must turn in next time.
●  Do not allow them to bring cellphones and MP3 players to the class at all.
■  Decide10formal and informal the class will be.

2014年12月12日14时，全长1432公里的南水北调中线一期工程正式通水。南水北调中线工程是为了缓解我国（　　）

如图甲所示，一矩形线圈位于随时间t变化的匀强磁场中，磁感应强度B随t的变化规律如图乙所示．以i表示线圈中的感应电流，以图甲中线圈上箭头所示方向为电流正方向，以垂直纸面向里的磁场方向为正，则以下的i﹣t图象中正确的是（   ）

下列说法中，你认为最符合实际的是(   )