用所给单词的适当形式填空。

1. He was a natural leader, and when he ____ (command), everyone obeyed.

2. Theory ____ (base) on practice and in turn serves practice.

3. I am just ____ (request) that you keep him safe.

4. The girl ____ (recognize) her father and cried at once.

5. The meeting ____ (expect) to end in the morning.

二十八岁初产妇，正常妊娠，平素体健，无其他并发疾病；3h前破水，现出现规律宫缩，宫口2～3cm，宫缩时疼痛难以忍受，强烈要求分娩镇痛。

如果患者因故不能采用椎管内注射分娩镇痛，患者目前最宜选则下列哪种方式进行分娩镇痛（）

A.间断氧化亚氮（笑气）吸入镇痛

B.间断肌注哌替啶（度冷丁）镇痛

C.间断注射地西泮和吗啡镇痛

D.采用静脉PCA镇痛

E.静注硫喷妥钠镇痛