则D（ξ）的最大值为____．

①战时的资本积累 ②政府有效的财政政策

③科学技术的进步 ④马歇尔计划的推动           

    (D)

    How to talk to someone you don't know? It depends on the situation(情形).

    If one of your friends introduce you to a new friend, it would be OK to start talking about the person who introduces you. You may ask him/ her how they knew each other. Show you are interested in it, even if you aren't. Nod after he/ she talks. This will give you more time to listen to what he/ she says, and think about next question from his/ her talking.

    Now if you go to a class on the first day where you do not know anyone, the first thing you should remember is not to be shy when talking to other people. You may remember when you were in the first or second grade, someone would just walk up to you and talk to you. Be open, but think before you talk.

    When it comes to meeting people face to face for the first time, find a situation which both of you are in. Maybe you are sitting next to each other. Maybe the other person says something you don't understand. Find a situation that seems proper (恰当的). Start with a simple conversation. It may seem strange at first. But the more you talk and take action with them, the more they will like you.

国庆60周年的天安门庆典上，中国的女民兵方队表现出色，赢得了党和国家领导人***的高度评价，第一次露出了笑颜．假定这一列队伍行进速度是3m/s，经过天安门正前方200m的阅兵界线，从队伍第一人踏上界线到最后一人离开界线共需90s，则队伍长为（　　）

阅读下面的短文，掌握大意，然后从每题所给A、B、C、D四个选项中选出最佳选项。

Dear Betty,

    Thank you very much for your email. I know you are new here and come to Wenzhou in your car. You want to know something old in Wenzhou. You say you'd like 1 Wenzhou Museum. It is a big and famous 2. It is near Shiji Square. Let me tell you the way to it. Take your car from your hotel and 3 along Fudong Road. Turn left at the third turning, not the 4 one. You will see Wenzhou Library 5your left. The museum is opposite the library. It 6from 9:00 to 5:00pm every day, except Monday. There are lots of 7 things and paintings in the museum. I think you can enjoy yourself there.8 don't take a camera, you can't use 9 in the museum. There is a small shop next to it. You can buy some souvenirs in it. And if you have enough 10, Wenzhou Science and Technology Museum is next to it. It is a good place to have fun, too.

    I think you'll have a good time in Wenzhou!

Yours,

Tom