简述重力式挡土墙的破坏形式及原因有哪些？

My Family Is Very Poor

A little boy comes to a new city. His name is Peter. Of course（当然），he lives with his mother and father. His family is very rich（富裕的）. They have a driver（司机） and a lot of servants（仆人）.

Peter is going to a new school. On the first day his parents say to him，“ peter，be modest（谦虚的）at your new school. Don’t say we are rich. ”And Peter says，“ Yes，Dad，mom. ”

So Peter goes to school. He sees his new teacher. And he sits down with the other children. The teacher says. “Good morning，children. The first exercise today is a composition（作文）. The topic（题目） of the composition is ‘My Family’.”So every child writes a composition. This is Peter’s composition：

“My name is Peter. My family is very poor（贫穷）. Both my father and my mother are very poor. Our driver is very poor and all the servants are poor…”

根据短文内容，选择最佳答案。

小题1:Peter’s parents are very            .

A．small

B．modest

C． poor

D．rich小题2:Peter’s parents tell him not to          .

A．play on his way to school

B．be late for school

C．say they are rich

D．write a composition小题3:The teacher asks the children to write          .

A．a letter

B．a composition

C．a book

D．a story小题4:Peter writes a composition about his          .

A．friend

B．teacher

C．school

D．family小题5: Which of the following is right?

A．Peter tells a lie（说谎）in his composition.

B．Peter doesn’t like writing a composition.

C．Peter’s parents write the composition.

D．The teacher is very poor，too.

下列哪种肝炎病毒基因组为DNA

A．甲型肝炎

B．乙型肝炎

C．丙型肝炎

D．丁型肝炎

E．戊型肝炎

甲、乙、丙三位同学设计了一个实验结果各自都认为自己的试样中含有SO42-离子。甲的实验为：

(1)乙认为甲的实验不严谨，因为试样A中若含有____离子(仅填一种)，也会有此现象。乙的实验为：

(2)丙认为乙的实验也不严谨，因为试样B中若含有____(仅填一种)，也会有此现象。丙的实验</PGN0055B.TXT/PGN>为：

若丙方案合理，则回答：

(3)其中试剂Ⅰ是____，现象Ⅰ是____。

试剂Ⅱ是____，现象Ⅱ是____。(若你认为丙方案不合理，以上回答可以不填)。

偏瘫患者进行步行训练的基本要求是（）

A.患肢可以独立承担体重

B.站立平衡达到2级以上

C.能够主动配合训练

D.下肢必须有痛觉

E.必须使用矫形器

有关无色素性痣的叙述，下述不正确的是（）

A.是一种非痣细胞痣

B.是一种发生学上的畸形

C.是一种持续不退的疾病

D.是一种易发癌变的疾病

E.是一种不完全性色素脱失性疾病