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问题 选择题

呼吸作用的实质是（　　）

A．合成有机物，释放能量

B．分解有机物，储存能量

C．合成有机物，储存能量

D．分解有机物，释放能量

答案

呼吸作用是生物的基本特征，进行的场所是线粒体，表达式为：有机物+氧→二氧化碳+水+能量，在此过程中释放出大量的能量，一方面满足自身的需要，另一部分以热能的形式散失出去．所以呼吸作用的实质是分解有机物，释放能量．

故选：D．

单项选择题

邓 * * 提出，国际经济政治新秩序应该建立在( )原则的基础上。

A．独立自主

B．和平共处五项

C．反对霸权主义和强权政治

D．平等友好
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单项选择题

One ofthe main resposibilities of ICMP is to report(1).Although technology has produced increasingly relaible transmission media, errors still exist and must be handled. IP is an (2) protocol. This means that error checking and error control are not a concern of IP. ICMP was designed, in part, to compensate for this shortcoming. Howerver, ICMP does not (3) errors, it simply report them. Error correction is left to the higher-level potocols. Error messages are always sent to the original (4) because the only information available in the datagram about the route is the source and destination IP addresses. ICMP use the source IP address to sent the error massage to the source of the (5).

空白（5）处应选择（）

A.datagram

B.frame

C.service

D.protocol
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