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

### Instruction:
When was the parliament that was elected in 1509/10, and had an unknown second member, dissolved?

### Inputs:
table_name: table, columns: ['Elected', 'Assembled', 'Dissolved', '1st member', '2nd member']

### Response:
SELECT Dissolved FROM table WHERE 2nd member = unknown AND Elected = 1509/10