如下图所示，在载玻片上滴一滴草履虫培养液，左侧滴一滴清水，右侧滴一滴浓盐水，将这

栈是一种按“后进先出”原则进行插入和删除操作的数据结构，因此，（）必须用栈。

A．函数或过程进行递归调用及返回处理

B．将一个元素序列进行逆置

C．链表结点的申请和释放

D．可执行程序的装入和卸载

在判断试板与修补区色差时，会影响正确判断的因素有（）。

A．修补区域的光线

B．修补区域的周围环境

C．比色区原涂膜的老化层

D．比色区与试板的角度一致性

E．长时间的盯视

非风动卸砟车边走边卸时，先停车确认，应以（）时速边走边卸，并及时清理限界内的道砟。

A.5～10km/h

B.8～15km/h

C.10～15km/h

D.15～20km/h

男女强直性脊柱炎的主要差别是（）

A.男性HLA-B27阳性率大于90%，女性小于80%

B.男性预后较差，女性预后较好

C.男性病情重，女性病情轻

D.外周关节受累发生率女性多见

E.脊柱强直发生率女性较高

I live in the country and my father was a farmer.51. ______
He is now forty-five year old. Because of years of 52. ______
hard work, he looks old than his age. When I was53. ______
young, he is used to tell me the importance of study. 54. ______
Father knows little about English and other subjects, 55. ______
but he usually gives me some good advices on how56. ______
to learn my lessons good. He is not only kind to me 57. ______
but also very strict in me. With his help, I’ve made 58. ______
great progress. I’ll never to forget what he taught 59. ______
me. I think my father is best father in the world. 60. ______