①四边形中四个内角可以都是锐角；

②四边形中四个内角可以都是钝角；

③四边形中四个内角可以都是直角；

④四边形中四个内角最多可以有两个钝角；

⑤四边形中最多可以有两个锐角.

其中正确的是（ 　　 ）

如图所示，将两个铅柱的底面削平、削干净，然后紧紧地压在一起，两铅块就会结合起来，甚至下面吊一个钩码都不能把它们拉开。这个实验现象说明了（）

图中，下列说法正确的是（　　）

    My name is Cathy. I'm a fourteen-year-old girl from England. Now I'm 1 in a middle school.I have to say that I was not good 2 my lessons before. So I was always afraid of exams.

    Last week I 3 my end-of-year exams. Today I got my report card. 4 ， I did very well. My mom and dad said it was the best report. It was 5 main subjects that the report card talked about， and I felt very 6 today. My teachers ticked( 给…打勾 ) “7 to improve”，“Good” or “Very good”. My English teacher said my English was much better. For math and science I also 8 “ Very good” ticks. All my teachers said I was 9 And at the end of the report card my head teacher said， “A very good 10. Well done!” I am so pleased with it，but I hope I can get a better report next year. I'm sure I can.