机械式停车设备检修时，应该怎样检查安全钳？

（5分）常温下，有下 * * 种溶液：①0.1 mol/L NH₄Cl  ②0.1 mol/L NH₄HCO₃   ③0.1 mol/L NH₄HSO₄           

请根据要求填写下列空白：

（1）溶液①呈  性（填“酸”、“碱”或“中”），其原因是：

                                            （用离子方程式表示）

（2）比较溶液②、③中c(NH₄⁺)的大小关系是②          ③﹝填“＞”、“＜”或“＝”）

Controversy has been aroused about the works of Jin Yong, a famous martial-arts fiction writer in China, being used in the students’ Chinese textbooks. Some experts in the field of education welcome the practice, while others are ply against it.

Topic: Should martial-arts fictions be integrated into the Chinese textbook

Questions for Reference:
1. Some people think the martial-arts fictions full of violence and romance are not suitable for the students. What’s your opinion
2. What do you think are the advantages and disadvantages of Jin Yong’s martial-arts fictions as textbook material
3. What are the possible negative effects and how can we reduce them

检测大病毒颗粒（如痘类病毒）和病毒包涵体，适合选用的显微镜（）。

A.普通光学显微镜

B.暗视野显微镜

C.倒置显微镜

D.荧光显微镜

E.电子显微镜

女性，47岁，胆囊结石病史4年，曾先后发作性胆绞痛4次，BUS显示胆囊内充满结石。首选的治疗方法是下列哪一种（）

A.口服熊去氧胆酸片

B.口服排石饮液

C.口服利胆素片

D.胆囊切除术

E.经皮胆镜取石术

人工呼吸时压迫环状软骨的目的是什么？