人体软组织中的声速大约是()
A.1540m/s
B.350m/s
C.4500m/s
D.3000m/s
E.7000m/s
参考答案:A
-What a beautiful watch! Is it new?
-No, I have ____ it for two years. [ ]
A. had
B. sold
C. borrowed
D. bought
易复性疝为
A.疝内容物易回纳入腹腔B.疝内容物为部分肠壁C.疝内容物不能完全回纳入腹腔D.疝内容物有动脉性血循环障碍E.疝内容物被疝环卡住不能还纳,但无动脉性循环障碍