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【简答题】
给出下列命题： ①关于x的不等式（a-2）x 2 +（a-2）x+1＞0的R的充要条件是2＜a＜6； ②我们定义非空集合A的真子集的真子集为A的“”，则集合{1，3，5，7，9}的“”有26个． ③已知f（x）=ax 2 +bx+c（a≠0），若方程f（x）无实数根，则方程f[f（x）]=x也一定没有实数根； ④若{a n }成等比数列，S n 是前n项和，则S 4 ，S 8 -S 4 ，S 12 -S 8 成等比数列． 其中正确命题的序号是______．
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皮皮学刷刷变学霸
举一反三
【单选题】when will they visit the National Library? 查看材料
A.
On Tuesday．
B.
On Wednesday．
C.
On Thursday．
D.
On the weekend．
查看完整题目与答案
【多选题】to hold historical records in the National Library
A.
Seagate hard drive Superfast 8ms hard drive Capacity ranges from 80GB to 1TB .
B.
I omega portable hard drive 160GB, 2.5" external hard drive. An affordable way to back up all your data, from business documents to emails .
C.
Lacie DVD drive 16x DVD writer with free Nero DVD burning software . Can play and record both DVD+R and DVD-R discs, plus their rewritable counterparts, as well as all types of CD .
D.
Panasonic portable DVD player 8" portable LCD DVD Player with Car Kit. Compatible with D VD -video, CD, JPEG image CD and Mp3-formatted audio CD .
E.
Sony Blu-ray disc drive Sonys Vaio AR laptop is the first portable Blu-ray studio, which includes a Blu-ray disc drive and a TV tuner, alongside a 17" widescreen display and a 2GHZ Intel Core Duo processor .
F.
Toshiba USB flash drive High-speed 16GB pen drive with a built-in MP3 player . Plugs directly into any USB connection .
查看完整题目与答案
【判断题】比特是计算机信息存储的最小单位，字节是信息存储的基本单位。
A.
正确
B.
错误
查看完整题目与答案
【单选题】DNS(域名系统)完成的工作是从一种容易记忆的网络服务器域名到计算机容易处理的( )之间的映射。 cl14
A.
域名地址
B.
URL地址
C.
主页地址
D.
IP地址
查看完整题目与答案
【多选题】考虑地基变形对上部结构的影响,根据刚度将建筑结构分为( )几类。
A.
柔性结构
B.
绝对柔性结构
C.
刚性结构
D.
敏感性结构
E.
绝对刚性结构
查看完整题目与答案
【判断题】ios 是虚基类,不能用于定义对象。
A.
正确
B.
错误
查看完整题目与答案
【简答题】When will they visit the National Library?
查看完整题目与答案
【简答题】The National Library of Iceland is a reference library, which means books and other items in our collections cannot be browsed or borrowed, and must be ordered for consulation(查阅) in our reading rooms...
查看完整题目与答案
【判断题】ios 是虚基类，不能用于定义对象。
A.
正确
B.
错误
查看完整题目与答案
【简答题】You planned to go to the National Library with your friend tomorrow. But now you have an important job interview. Write an email to him/her to 1)make an apology, 2)ask for advice for the interview. Do...
查看完整题目与答案
相关题目：
【单选题】when will they visit the National Library? 查看材料
A.
On Tuesday．
B.
On Wednesday．
C.
On Thursday．
D.
On the weekend．
查看完整题目与答案
【多选题】to hold historical records in the National Library
A.
Seagate hard drive Superfast 8ms hard drive Capacity ranges from 80GB to 1TB .
B.
I omega portable hard drive 160GB, 2.5" external hard drive. An affordable way to back up all your data, from business documents to emails .
C.
Lacie DVD drive 16x DVD writer with free Nero DVD burning software . Can play and record both DVD+R and DVD-R discs, plus their rewritable counterparts, as well as all types of CD .
D.
Panasonic portable DVD player 8" portable LCD DVD Player with Car Kit. Compatible with D VD -video, CD, JPEG image CD and Mp3-formatted audio CD .
E.
Sony Blu-ray disc drive Sonys Vaio AR laptop is the first portable Blu-ray studio, which includes a Blu-ray disc drive and a TV tuner, alongside a 17" widescreen display and a 2GHZ Intel Core Duo processor .
F.
Toshiba USB flash drive High-speed 16GB pen drive with a built-in MP3 player . Plugs directly into any USB connection .
查看完整题目与答案
【判断题】比特是计算机信息存储的最小单位，字节是信息存储的基本单位。
A.
正确
B.
错误
查看完整题目与答案
【单选题】DNS(域名系统)完成的工作是从一种容易记忆的网络服务器域名到计算机容易处理的( )之间的映射。 cl14
A.
域名地址
B.
URL地址
C.
主页地址
D.
IP地址
查看完整题目与答案
【多选题】考虑地基变形对上部结构的影响,根据刚度将建筑结构分为( )几类。
A.
柔性结构
B.
绝对柔性结构
C.
刚性结构
D.
敏感性结构
E.
绝对刚性结构
查看完整题目与答案
【判断题】ios 是虚基类,不能用于定义对象。
A.
正确
B.
错误
查看完整题目与答案
【简答题】When will they visit the National Library?
查看完整题目与答案
【简答题】The National Library of Iceland is a reference library, which means books and other items in our collections cannot be browsed or borrowed, and must be ordered for consulation(查阅) in our reading rooms...
查看完整题目与答案
【判断题】ios 是虚基类，不能用于定义对象。
A.
正确
B.
错误
查看完整题目与答案
【简答题】You planned to go to the National Library with your friend tomorrow. But now you have an important job interview. Write an email to him/her to 1)make an apology, 2)ask for advice for the interview. Do...
查看完整题目与答案