坐位时胸段脊柱呈均匀性向后弯曲，仰卧位时弯曲消失的疾病是（）
A.佝偻病
B.强直性脊柱炎
C.胸椎结核
D.脊柱退行性变
E.脊柱外伤
参考答案：A
Don’t use your cellphone — we are flying at ____ altitude of 10,000 meters and ____average speech is 678km/h.
A．an; the
B．the; the
C．the; an
D．an; an
病变远端呈杯口状充盈缺损，周围有多个弹簧状环形阴影的是（）
A.单纯性小肠梗阻
B.绞窄性小肠梗阻
C.单纯性结肠梗阻
D.结肠扭转
E.肠套叠
