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问题 单项选择题

某墙背倾角a为10°的俯斜挡土墙，若墙背与土的摩擦角δ为10°，则被动土压力合力与水平面的夹角为：（）

A.20°

B.30°

C.10°

D.0°

答案

参考答案：D

解析：被动土压力合力与水平面的夹角为δ～a，墙背俯斜时，a取正值，墙背仰斜时，a取负值。

填空题

[听力原文] 11-15

A mother and her seven-year-old daughter were resting in their room in a big hotel in Thailand when (11)(15) suddenly a fire broke out. Very soon thick black smoke started to come into their room and there was hardly any air. (15)Their lives were in danger. The mother opened the door only to find that the hall way was also (12)full of smoke (15)She ran to the telephone to call for help, but the line was dead, Then she put (13)wet towel over her daughter’s face and her own so that they could breathe. Later firefighters lowered a rope from the hotel roof to their window level and (15) pulled them up to the roof. (14) Eighty-four people were killed in the fire and (15)fortunately they were saved.

In order to breathe, what did the mother put over their faces
（）
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单项选择题 共用题干题

患者女，26岁，近1个月反复出现中上腹饥饿痛，偶有夜间痛，伴反酸，嗳气。胃镜检查提示：“十二指肠球部溃疡”，快速尿素酶试验呈阳性。近期无解热止痛药服用史。

疗程结束后若患者症状完全缓解，下一步应该（）。

A.停药后立即复查胃镜

B.停药后立即检测粪便幽门螺杆菌抗原

C.停药后立即检测血清幽门螺杆菌抗体

D.停药4周后进行13C或14C呼气试验检测

E.停药后无须再行任何检查
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