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

### Instruction:
What Russian has an Avoirdupois value of 0.686 gr?

### Inputs:
table_name: table, columns: ['Unit', 'Russian', 'Ratio', 'Metric value', 'Avoirdupois value']

### Response:
SELECT Russian FROM table WHERE Avoirdupois value = 0.686 gr