某病人2小时呕血,量多,有血块,测血压仅在60mmHg处听到1次搏动,其失血量为总血容量的
A小于15%
B15%~20%
C20%~30%
D30%~40%
E>40%
参考答案:E
He was sitting there ________ his cigarette. Without any words, he seemed to be ________ deep
thought. [ ]
A. at; in
B. over; in
C. with; at
D. with; over
桥接器可以为业务忙的网络分段从而来减少每段上的通信量以及提高性能。同时它还可以过滤网络广告信息,只允许必要的通信信息通过桥接器到达另外的网络。