user: Question: Who wrote the episodes with 7.70 u.s. viewers (million) ?
Columns: ['No. in series', 'No. in season', 'Title', 'Directed by', 'Written by', 'Original air date', 'Production code', 'U.S. viewers (million)']
Types: ['real', 'real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [36.0, 1.0, '" Chuck Versus the Pink Slip "', 'Robert Duncan McNeill', 'Chris Fedak & Matt Miller', 'January10,2010', '3X5801', '7.70']
SQL:

assistant: SELECT "Written by" FROM "Table" WHERE "U.S. viewers (million)" = '7.70';