委托指令有多种形式，可以按照不同的依据来分类。从各国(地区)情况看，一般根据( )，有买进委托和卖出委托。

A．委托订单的数量
B．买卖证券的方向
C．允许买空卖空
D．委托价格限制

The boss took it for granted that his secretary should keep him well-informed.

A．assumed that it was true without doubt

B．believed that it was true without making sure

C．agreed that it was necessary

D．thought that it was beneficial