为什么水杨酰胺比水杨酸甲酯水解困难？

句型转换。

1. We are in Beijing. (就划线部分提问)      

_____ _____ we?  

2. Can you bring the ruler to me? (作出否定回答)      

No, _____ _____.   

3. I draw pictures on the wall. (变为否定句)      

I _____ _____ pictures on the wall.  

4. We have two new students in our class. (变为同义句)      

_____ _____ two new students in our class.  

5. There's an English book in the desk. (变为复数句)      

_____ _____ English _____ in the desks.

她急匆匆地赶到图书馆去( )有关笔迹鉴定的材料。

A．查询

B．查阅

C．翻阅

D．阅读

下列关于标准成本与目标成本的说法中正确的是( )。

A．目标成本一般适用于产品品种较少的大批量生产企业

B．标准成本的制定，从最基层的作业开始，分别规定数量标准和价格标准，逐级向上汇总，形成单位标准成本

C．标准成本是成本管理与目标管理结合的产物，强调对成本实行目标管理

D．标准成本的确定从企业的总目标开始，逐级分解成基层具体目标

漫画起源于（）国家

When the system upon which a transport entity is running fails and subsequently reatarts, the ______ information of all active connections is lost. The affected connections become half-open, as the side that did not fail does not yet realize the promble.
The still active side of a half-open connections using a ______ timer. This timermeasures the time transport machine will continue to await an ______ of a transmitted segment after the segment has been retransmitted the maximum number of times. When the timer ______, the transport entity assumes that either the other transport entity or the intervening network has failed. As a result, the timer closes the connection, and signals an abnormal close to the TS user.
In the event that a transport entity fails and quickly restart, half-open connections can be teminated more quickly by the use of the RST segment. The failed side returns an RST_i to every segment i that it receives. When the RST_i reaches the other side, it must be checked for validity dased on the ______ number i, as the RST could be in response to an old segment .If the reset is valid, the transport entity performs an abnormal termination.

A. expires B. restarts C. stops D. abandons