Final answer:
The three phonograms that say /ow/ sounds like /awh/ are ou, ow, and au. The phonogram that is not common is au.
Step-by-step explanation:
The three phonograms that say /ow/ sounds like /awh/ are ou, ow, and au.
For example, in the word house, the ou is pronounced as /awh/. In the word cow, the ow is pronounced as /awh/. And in the word Paul, the au is pronounced as /awh/.
The phonogram that is not common is au. While ou and ow are commonly used to represent the /ow/ sound like /awh/, au is less common.