如图，菱形ABCD中，∠B=60°，点E在边BC上，点F在边CD上．若EB=2，DF=3，∠EAF=60°，则△AEF的面积等于____．

晴朗的白天进入植物体叶片气孔和从叶片中通过气孔散失的气体依次是（　　）

《共产党宣言》是近年来美国教育部公布的“美国中学生必读书目”之一，通过阅读《共产党宣言》，美国中学生可以了解（ ）
（1）资本主义社会的基本矛盾（ 2）无产阶级革命首先在一个落后国家取得胜利的原因  
（3）巴黎公社的经验教训     （4）世界无产阶级的历史使命

选择下列词汇完成下面对话。并在答题卡上将相应的字母编号涂黑．

A. take   B. where   C. present   D. enjoyed   E. pleasure   F. broke down

A: Hello, Jim!
B: Hello, Wei Hua!
A: Thanks for inviting me to your birthday party yesterday evening. I ____ it very much.
B: Thank you for your nice present!
A: It was my ____ !
B: By the way, ____ are you going?
A: I’m going to see Uncle Wang. My radio ____  last week. I took it to him to repair yesterday. I'm going to get it back.
B: May I go with you?
A: Why not? His home is not far away from here. It'll____  us about ten minutes.
B: OK! Let's go.

为了方便行人推车过某天桥，市政府在10m高的天桥一侧修建了40m长的斜道（如图所示），我们可以借助科学计算器求这条斜道倾斜角的度数，具体按键顺序是（   ）