螺纹画法规定，外螺纹的大径（牙顶）用（）表示。
A.细实线
B.点划线
C.粗实线
D.虚线
参考答案：C
等渗性脱水患者补液治疗首先应输入的是（）
A.右旋糖酐
B.5%葡萄糖液
C.5%碳酸氢钠溶液
D.10%葡萄糖液
E.5%葡萄糖盐水
The old man got sick last summer and ______in bed since then . [ ]
A. was
B. had been
C. has been
D. would be
