Under the current system, schools and districts are largely on their own to find acceptable substitutes.

What I want is not an acceptable substitute, but a reason to switch.

It's a matter now of whether he wants me alive, or whether dead is an acceptable substitute.

The energy burned less efficiently, but was an acceptable substitute.

In the absence of hair on the head, body hair can be used as an acceptable substitute.

Utility personnel are not an acceptable substitute, either legally or practically.

But those ingredients alone do not constitute an acceptable substitute.

An arbitrary decision by the president is not an acceptable substitute for due process.

Going forward is banned: in the future is an acceptable substitute.

Our zoning is built on the idea that that's an acceptable and appropriate modern substitute.