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问题 单项选择题

以下哪个选项不属于以太网的“543”原则？（）

A.5个网段

B.4个中继器

C.3个网段可挂接设备

D.5个网段可挂接

答案

参考答案：D

选择题

Read and guess.(看句子，猜谜语)

1. It's an animal. It lives in Australia.  It lives in trees. It's _____.     [ ]

A. a kangaroo                

B. a koala                      

C. a monkey

2. It's a place. Our parents always go there at the weekend.  We buy many things from it. It's a _____.    

[ ]

A. supermarket              

B. park                        

C. library

3. When do we use umbrella and boots? It's _____.     

A. rainy                    

B. sunny                      

C. windy

4. It's a thing. When you go on a trip and take some pictures, you will take it. It's a _____.     [ ]

A. tent                      

B. umbrella                    

C. camera

5. What has hands but no feet, a face but no eyes, tells but does not talk? It's a _____ .           [ ]

A. table                    

B. blackboard                  

C. clock
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单项选择题 A1/A2型题

下列一般不会出现黑便的是（）

A.消化性溃疡活动期

B.肛裂

C.进食鸭血

D.服用含有铁剂

E.胃癌
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