We are thinking of placing an order.

我们正在考虑订货。

Placing an order is a central use case in our scenario.

下订单在我们的场景中是一个重要用例。

Interval between placing an order and receiving delivery.

收到订单和收到货物的时间间隔。

Before placing an order to buy a stock, check the asking price.

下单买股票之前，先查一下卖价。

The other problem is that I am excepting placing an order myself.

另外一个问题是我在等待给我一个付款指令让我开始业务。