【单选题】
On the morning of November 18,1755, an earthquake shookBoston, Massachusetts.
John Winthrop, a professor at HarvardCollege, felt the quake and awoke. “I rose,” Winthrop wrote, “and lighting a candle, looked on my watch, and found it was 15 minutes after four.”John Winthrop went downstairs to the grandfather clock. It had stopped four minutes before, at 4:11.Except for stopping the clock, the quake had only thrown a key from the mantel (壁炉台) to the floor.The clock had stopped because Winthrop had put some long glass tubes he was using for an experiment into the case for care. The quake had knocked the tubes over and blocked the pendulum (钟摆). Winthrop, therefore, had the exact time that the earthquake had hitBoston. He looked at the key on the floor. The quake had hrown it forward in the direction of the quake’s motion (运动) by a shock coming from the northwest, perhaps inCanadA、