On the morning of November 18,1735, an earthquake shook Boston, Massachusetts. John Winthr
The clock had stopped because Winthrop had put some long glass tubes he was using for an experiment into the box for safekeeping. The quake had knocked the tubes over and blocked the pendulum. Winthrop, therefore, had the exact time that the earthquake had hit Boston. He looked at the key on the floor. The quake had thrown it forward in the direction of the quake's motion by a shock coming from the northwest, perhaps in Canada.
This passage suggests that ______.
A.John Winthrop had difficulty in sleeping
B.earthquakes are common in Boston
C.Boston was a center for clock-making
D.John Winthrop was a scientist