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问题 单项选择题

分别将等pH或等物质的量浓度的盐酸和醋酸等体积混合，加入足量镁，产生H2的体积（同温同压下测定）的变化图示如下：

其中正确的是（）。

A．①③

B．②④

C．①②③

D．①②③④

答案

参考答案：D

单项选择题

One of the main responsibilities of ICMP is to report ______. Although technology has produced increasingly reliable transmission media, errors still exist and must be handled. IP is an ______ protocol. This means that error checking and error control are not a concem ofIP JCMP wasdesigned, in part, to compensate for this shortcoming. Howerver, ICMP does not ______ errors, itsimply reports them. Error correction is left to the higher-level protocols. Error messages arealways sent to the original ______ because the only information available in the datagram aboutthe route is the source and destination 1P addresses. ICMP uses the source IP address to send theerror massage to the source of the ______.

A．datagram
B．frame
C．service
D．Protocol
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单项选择题

（），国务院下发了《关于今后在行文中和书报杂志里一律不用“满清”称谓的通知》。

A.1950年

B.1955年

C.1956年

D.1958年
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