失血性休克通常在短时间内失血量超过全身血量的()。
A.10%
B.20%
C.30%
D.40%
E.50%
参考答案:B
The development of industry has been ________ gradual process throughout ________ human existence, from stone tools to modern technology. [ ]
A. 不填; the
B. the; a
C. a; 不填
D. a; a
建立新连接可以建立()个新连接
A、1
B、2
C、3
D、若干