____ will he be back? 
In a week.　

1. A.
   How long
2. B.
   How soon
3. C.
   How often
4. D.
   How many

____ will he be back? 
In a week.　

____ will he be back? 

In a week.　

A．How long          B．How soon          C．How often         D．How many