不属于年轻恒牙牙髓特点的有
A．组织疏松
B．血运丰富
C．防御修复机强
D．渗出作用强
E．增生现象显著
参考答案：D
Little did he care about his own safety,_______he was in danger himself.
A．if
B．though
C．since
D．because
在采购订单或进货单制单时，可供选择的付款方式有（）
A.全额现结
B.全额订金
C.月结
D.限期付款
