搜题请搜索小程序“爱下问搜题”
问题 填空题
在-
1
7
，3.14，
311
，
25
，0.575775777…（两个5之间依次多一个7）中，属于无理数的有______个．
答案

无理数有：

311
，0.575775777…（两个5之间依次多一个7），共有2个．

故答案是：2．

单项选择题

加油站的报警及监控系统由当地（）授权的专门企业生产、安装，并负责日常维修。

A、消防部门

B、公安机关

C、工商部门

D、技术监督局
查看答案
单项选择题

Electronic mail and filing permit a user to compose and transmit a message on an office (71) system. In the early 1970s, the ARPANET community developed a number of such systems which have been heavily used. Through standard message format (72) , several hundred different computers and electronic mail interfaces are specification of how (73) and return addresses should appear on envelopes and which sizes are allowable for envelopes. In the electronic message world, they describe what (74) of characters are required at the (75) of a message to identify the sending and receiving mailboxes.

A．end

B．last

C．initiation

D．beginning
查看答案