自来水龙头内直径2厘米，里面水流速度是每秒1米，打开水龙头，1分钟流出水____

以下程序的功能是将字符串s中所有小写字母’a’删去，请填空。 #include＜stdio.h＞ main() {char s[]="absuWWUDJFKFLaaakdK"; int i,j; for(i=j=0;s[i]!=’\0’;i++) if( ) s[j++]=s[i]; s[j]=’\0’; printf("%s",s); }

口角的正常位置约相当于（）。

A.侧切牙与尖牙之间

B.尖牙与第一双尖牙之间

C.第二双尖牙与第一磨牙之间

D.第二双尖牙与第一双尖牙之间

E.第二磨牙与第一磨牙之间

未经许可不得更改房内任何建筑设施，严禁遮挡，损坏挪用库房内的（）设施。

“碧云天，黄叶地，北雁南飞”语出《红楼梦》。

The network layer provides services to the transport layer. It can be based on either___20___. In both cases, its main job is ___21___ packets from the source to the destination.

In network layer, subnets can easily become congested, ncreasing the delay and ___22___ for packets. Network designers attempt to avoid congestion by proper design. Techniques include___23___ policy, caching, flow control, and more.

The next step beyond just dealing with congestion is to actually try to achieve a promised quality of service. The methods that can be used for this include buffering at the client, traffic shaping, resource___24___, and admission control. Approaches that have been designed for good quality of service include integrated services (including RSVP), differentiated services, and MPLS.

23（）

A. abandonment

B. retransmission

C. checksum

D. synchronism