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问题 单项选择题 A1型题

低氧刺激呼吸活动增强，其作用机制是（）

A.兴奋延髓呼吸中枢

B.兴奋脑桥呼吸调整中枢

C.兴奋中枢化学感受器

D.兴奋中脑呼吸中枢

E.兴奋外周化学感受器

答案

参考答案：E

解析：对于低氧刺激敏感的化学感受器只存在于外周，即颈动脉体和主动脉体上。当发生低氧时，可引起其兴奋，通过神经冲动传入呼气中枢，引起呼吸加深加快，纠正低氧，故答案D最正确。但是整个过程是在延髓呼吸中枢控制下实现的。

阅读理解

Two men are walking in the park. One is Mr. Brown, a worker, the other is Mr. Black. Mr. Brown is going to a chair. It is next to the road. Mr. Black is after him. Mr. Brown finds Mr. Black. Now Mr. Black begins to walk faster (更快). Because he wants to get to the chair before Mr. Black. Now Mr. Black begins to walk faster because he also wants to get to the chair first. Then they both run. Mr. Black runs faster than (比) Mr. Brown. So he gets to the chair first and sits down on it. Mr. Brown runs after Mr. Black. When he gets to the chair. He sees Mr. Black sitting on it. He is sorry to show a notice(通知)with the words“Wet Paint(油漆未干)”to Mr. Black. Now Mr. Black knows why Mr. Brown is going to the chair.

小题1:Where are Mr. Brown and Mr. Black?

A．In the garden

B．On the chair

C．In the park

D．Next to the road小题2:What are they doing? They are________

A．talking

B．walking to the chair

C．holding a notice

D．sitting on a chair小题3:________is after _________at first

A．Mr. Black , Mr. Brown

B．The worker, Mr. Brown

C．Mr. Brown ,Mr. Black

D．Mr. Brown The worker小题4:________get to chair first.

A．The worker

B．Mr. Brown

C．Mr. Black

D．A student小题5:Mr. Brown goes to the chair because__________.

A．he wants to sit there

B．it is his chair

C．he wants to talk to Mr. Black on the chair

D．he wants to tell people “Wet Paint”
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单项选择题

在同一构件混凝土浇筑之前，钢筋验收时不符工艺要求的为（）。

A.钢筋绑扎搭接接头连接区段的长度为1.3ll等。

B.相邻钢筋接头的位置在同一位置上。

C.绑扎搭接接头中钢筋的横向净距不应小于钢筋直径，且不应小于25mm。

D.纵向受拉钢筋搭接接头面积百分率应符合设计要求。
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