跖筋膜起源于()
A．距骨外侧缘
B．跟骨结节内侧
C．跟骨外侧缘
D．载距突
E．近端趾骨基底
参考答案：B
This problem is ______ difficult __________.
A．so; that few of us can do
B．so; that few of us can do it
C．too; for anyone of us to do
D．too; for anyone of us to do it
上升管、集气管都属于荒煤气导出设备。
