渐开线圆柱齿轮是()的展开线
A.齿根圆
B.齿顶圆
C.基圆
D.分度圆
参考答案:C
Though my sister often makes me ______, she was made ______ by me today. [ ]
A. cry; crying
B. crying; crying
C. cry; to cry
肺心病患者处于肺、心功能失代偿期,其主要临床表现是()
A.呼吸困难
B.咯血
C.胸闷、胸痛
D.休克
E.呼吸衰竭与右心衰竭