Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| No. in series | No. in season | Title | Directed by | Written by | Original U.S. air date | Prod. code | Viewers (millions) |
| --- | --- | --- | --- | --- | --- | --- | --- |
| 50.0 | 1.0 | "The Silent Treatment" | Phill Lewis | Dan Signer | July2,2010 | 305.0 | 3.4 |
| 51.0 | 2.0 | "Rat Tale" | Joel Zwick | Jeff Hodsden & Tim Pollock | July9,2010 | 308.0 | N/A |
| 52.0 | 3.0 | "So You Think You Can Date?" | Joel Zwick | Mark Amato & Sally Lapiduss | July16,2010 | 306.0 | 3.4 |
| 53.0 | 4.0 | "My Oh Maya" | Joel Zwick | Jeff Hodsden & Tim Pollock | July23,2010 | 301.0 | N/A |
| 54.0 | 5.0 | "Das Boots" | Carl Lauten | Pamela Eells O'Connell | July30,2010 | 303.0 | N/A |
| 55.0 | 6.0 | "Bon Voyage" | Adam Weissman | Adam Lapidus | August20,2010 | 304.0 | 4.0 |
| 56.0 | 7.0 | "Computer Date" | Joel Zwick | Jeny Quine | August27,2010 | 302.0 | N/A |
| 57.0 | 8.0 | "Party On!" | Joel Zwick | Jeff Hodsden & Tim Pollock | September10,2010 | 309.0 | 4.0 |
| 58.0 | 9.0 | "Love and War" | Eric Dean Seaton | Jeny Quine | September24,2010 | 311.0 | 2.8 |
| 60.0 | 11.0 | "The Ghost and Mr. Martin" | Joel Zwick | Adam Lapidus & Jeny Quine | October8,2010 | 310.0 | 3.3 |
| 61.0 | 12.0 | "Senior Ditch Day" | Phill Lewis | Mark Amato & Sally Lapiduss | October22,2010 | 320.0 | 3.5 |
| 62.0 | 13.0 | "My Sister's Keeper" | Phill Lewis | Jeny Quine | November5,2010 | 315.0 | 3.2 |
| 63.0 | 14.0 | "Frozen" | Phill Lewis | Dan Signer | November27,2010 | 312.0 | N/A |
| 64.0 | 15.0 | "A London Carol" | Shelley Jensen | Jeff Hodsden & Tim Pollock | December3,2010 | 313.0 | 4.1 |
| 65.0 | 16.0 | "The Play's the Thing" | Joel Zwick | Pamela Eells O'Connell | January7,2011 | 314.0 | 3.6 |
| 66.0 | 17.0 | "Twister: Part 1" | Bob Koherr | Adam Lapidus | January14,2011 | 316.0 | 4.4 |
| 67.0 | 18.0 | "Twister: Part 2" | Bob Koherr | Jeff Hodsden & Tim Pollock | January15,2011 | 317.0 | 5.2 |
| 68.0 | 19.0 | "Twister: Part 3" | Bob Koherr | Dan Signer | January16,2011 | 318.0 | 7.1 |
| 69.0 | 20.0 | "Snakes on a Boat" | Phill Lewis | Dan Signer & Adam Lapidus | March4,2011 | 319.0 | 3.8 |
| 70.0 | 21.0 | "Prom Night" | Eric Dean Seaton | Jeff Hodsden & Tim Pollock | March18,2011 | 321.0 | 3.02 |
Question:
Who was the directed for the episode titled "twister: part 1"?
Answer:
Bob Koherr