A

    Nick, 13, is tall and strong. He is good at running. Two weeks ago a new student came. His name is David. He is thin and short. He plays soccer well, and he can run very fast. Larry told Nick about it. Of course, Nick did not believe it.

    “Why not have a race with him?” said Larry.

    “Good idea!” said Nick. “I'll have a race with him after school.”

    After school, Nick went to the playground. He did some warm-up exercises for half an hour, and got ready for the race. He was sure that he could win it. Larry had to take part in a club activity that afternoon, so he could not watch the race between Nick and David.

    That evening Larry went to see Nick. They began to talk about the afternoon race. Nick's grandmother heard them in the next room. She came in and asked, “Which place?”

    “The second place,” answered Nick.

    His grandmother was very happy to hear that, and asked, “Which place did David win, then?”

    “The last but one.”

如图所示，MN是流速稳定的河流，河宽一定，小船在静水中的速度大小一定，现小船自A点渡河，第一次船头沿AB方向与河岸上游夹角为α，到达对岸；第二次船头沿AC方向与河岸下游夹角为β，到达对岸，若两次航行的时间相等，则（   ）

POS刷卡机的广泛应用给人们的生活带来了便利．POS机的刷卡位置有一个绕有线圈的小铁环制成的检测头（如图所示）．在使用时，将带有磁条的信用卡在POS机指定位置刷一下，检测头的线圈中就会产生变化的电流，POS机便可读出磁条上的信息．图中能反映POS刷卡机读出信息原理的是（　　）

    New Year's Day is coming. The students in Class 8 are preparing for a New Year's party. Cindy and Mary are malting red paper birds They want to put them outside (在……外面) the classroom  Lily and Alice are cleaning the desks and chairs They want a clean classroom. There are some pictures on the walls and there are also some beautiful flowers on the desks. Some boy students are learning taijiquan in the playground. They want to show (展示) it at the party. Where are Jack and Nancy? Oh, they are still in the shop. They are buying some food and drinks for the party. "We are very happy because we can have a big party," says Mike, the monitor (班长).