Task: Question Answering
Input (English): Passage: Week 10 featured the top-ranked defenses (by yardage against) in each conference, as the Lions hosted the Dolphins. Detroit got off to a quick start. Matt Prater kicked a 26-yard field goal on the opening drive of the game. Later in the first quarter, Calvin Johnson, playing in his first game since Week 5, caught a 49-yard TD pass from Matthew Stafford for a 10-0 lead. Miami managed a 23-yard Caleb Sturgis field goal before halftime, making the score 10-3. The Dolphins took the lead in the third, starting with a 50-yard Stugis field goal. Next, Earl Mitchell blocked Prater's 42-yard field goal attempt, and Dion Jordan returned the ball to the Lions 3-yard line. On the next play, Ryan Tannehill connected with Mike Wallace for the touchdown, putting Miami ahead, 13-10. Prater made good on a 50-yard field goal early in the fourth quarter to knot the score at 13-13, but Sturgis' 20-yarder put Miami back on top by 3. As in the previous two games, the Lions had to rally on their final drive to win the game. Starting at their own 26 with 3:13 left in the game, the drive culminated with Stafford's 11-yard touchdown pass to Theo Riddick, putting the Lions ahead for good, 20-16. This was the third straight game in which the Lions trailed at the two-minute warning, then went ahead on their final drive. It was the second time in a month that Miami had lost a game in the final seconds, following a Week 7 loss to Green Bay in which the final touchdown was scored with 3 seconds remaining. According to STATS Inc., this is the first time Detroit has started a season 7-2 since 1993. 
Question: How many points did Dolphins trail by halftime? 
Answer type: Number 
Output (English): 7.