所有运煤机（如龙门抓煤机、坦克抓煤机、扒煤机、推煤机、斗链运煤机等）应保持（），并定

M: Jane missed class again, didn’t she I wonder why.
W: Well, I knew she had been absent all week. So I called her this morning to see if she was sick. It turned out that her husband was badly injured in a car accident.
Q: What does the woman say about Jane()

A. She was absent all week owing to sickness.

B. She was seriously injured in a car accident.

C. She called to say that her husband had been hospitalized.

D. She had to be away from school to attend to her husband.

20世纪50年代中期以后的近二十年间，苏联经济持续高速发展，成为仅次于美国的世界第二号资本主义经济大国。

错误：___________________________

改正：___________________________

患者女，52岁，右上腹疼痛5天，伴皮肤巩膜轻度黄染，发热38.5℃，2小时前突然呕血约300ml。B超：肝内多发肝脓肿征象。既往肝内胆管结石病史，无慢性肝病史。 本患者上消化道出血的原因考虑为（）

A.胃、十二指肠溃疡

B.门脉高压症

C.出血性胃炎

D.胆道出血

E.胃癌

以下有关联合用药的叙述中，最合理的是（）

A.给病人无根据地使用多种药物

B.为减少药物不良反应而联合用药

C.合用含有相同活性成分的复方制剂

D.多名医师给同一病人开具相同的药物

E.提前续开具处方造成同时使用相同的药物

为什么防爆面要涂上防锈油？