The manager promised to keep us of how our business was going on.A. being informedB. infor

问题补充：

The manager promised to keep us of how our business was going on.

A. being informed

B. informed

C. informing

D. to be informed

答案：

A. being informed

(答案→)B. informed

C. informing

D. to be informed

解析：句意：经理答应让我们及时了解我们的生意进行的情况。inform sb of sth告诉某人某事；其被动：sb be inform of这里是keep sb done,这里sb与do之间是被动关系，故选B。