下列选项中，不属于用来控制催化剂循环量的阀门是（）。
A、再生单动滑阀
B、双动滑阀
C、待生单动滑阀
D、塞阀
参考答案：B
B2C通用支付平台支付不支持（）等支付模式。（只支持即时和授权支付）
A．即时支付
B．延时支付
C．委托支付
D．托管支付
An analyst does research about order types. The investor wants to profit from a predicted declines in the price of a company which she does not currently own. The most appropriate type of order is:
A. short sale.B. limit order.C. stop loss order.
