朱砂外用（）
A.清热解毒
B.镇心安神
C.养心安神
D.纳气平喘
参考答案：A
What operation on relations R and S produces the relation shown below { tuple | tuple∈R ∨ tuple∈S} ( )
A．union
B．difference
C．intersection
D．division
喇叭袖
