【多选题】专门性的学前儿童英语教育活动包括以下哪几项。
【单选题】听力原文: One of the banks worst hit by the international credit crisis,, the Citigroup, has outlined plans to dramatically reduce the size of its business. The bank's Chief Executive Vikram Pandit wants ...
A.
The Citigroup has been worst hit by the international credit crisis.
B.
The Citigroup has already started to reduce the size of its business.
C.
The Citigroup has encountered great losses in the credit crisis.
D.
The Citigroup has decided to take measures to deal with great losses.
【单选题】控制和治理CO 2 是解决温室效应的有效途径.将CO 2 转化成有机物可有效实现碳循环.CO 2 转化成有机物的例子很多,以下反应中,原子利用率最高的是( )
A.
6CO 2 +6H 2 O 光合作用 C 6 H 12 O 6 +6O 2
B.
CO 2 +3H 2 催化剂 △ CH 3 OH+H 2 O
C.
CO 2 +CH 4 催化剂 △ CH 3 COOH
D.
2CO 2 +6H 2 催化剂 △ CH 2 ═CH 2 +4H 2 O
【单选题】TCP协议是面向连接的协议,提供连接的功能是(1)______的;采用(2)_______技术来实现可靠数据流的传送。为了提高效率,又引入了滑动窗口协议,协议规定重传(3)_______的报文段,这种报文段的数量最多可以(4)________;TCP采用滑动窗口协议可以实现(5)_______。 (1) A.全双工 B.单工 C.半双工 D.单方向 (2)A.超时重传 B.肯定确认 C.超时重传和...
【单选题】●一台PC服务器,安装Linux并配置DNS服务。检查文件 (47) 发现内容为'order hosts'。 (47)