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问题 问答题

如图所示是录音磁头的工作原理图．请你标出此时录音磁头线圈中的电流方向．

答案

由图可知：磁头的左边为S极，右边为N极．用右手握螺线管，让大拇指指向N极（右边），则四指指向螺线管中的电流方向，电流方向是“左上右下”．如图所示：

单项选择题

For each blank, choose the best answer from the four choices and write down on the answer sheet.
(11) is a protocol that a host uses to inform a router when it joins Or leaves an Internet multicast group.
(12) is an error detection code that most data communication networks use.
(13) is an interior gateway protocol that uses a distance vector algorithm to propagate routing information.
(14) is a transfer mode in which all types of information are organized into fixed form cells on an asynchronous or non-periodic basis over a range of media.
(15) is an identifier of a web page.

A．ICMP

B．SMTP

C．IGMP

D．ARP
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单项选择题

关于爱情，下列说法中不正确的是( )。

A．幼儿也有爱情体验
B．爱情有生理基础，包括性爱因素
C．爱情的基本倾向是奉
D．爱情是一种高级情感，不是低级情绪
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