Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
What is the average number of points for an Offenhauser L4 engine with a Trevis chassis?

### Inputs:
table_name: table, columns: ['Year', 'Entrant', 'Chassis', 'Engine', 'Points']

### Response:
SELECT AVG Points FROM table WHERE Engine = offenhauser l4 AND Chassis = trevis