属于市场商贸合同，交易范围较大，运行规则比较规范的合同是（）。
A.承包合同
B.委托合同
C.出让合同
D.交易合同
参考答案：D
设抛物线的顶点坐标为（2，0），准线方程为x=-1，则它的焦点坐标为______．
_____ shopping habits, Alipay was the preferred method of payment for 69% of Chinese shoppers. [ ]
A. In terms of
B. Instead of
C. From behind
D. In case of
