In the morning of November 18th，1755，an earthquake            56．＿＿＿＿

shook Boston．John，a professor at Harvard College felt a quake 57． ＿＿＿＿

and woke up．“I rose and found to be fifteen minutes past      58． ＿＿＿＿

four．” He hurried to downstairs to the clock． It had stopped 59． ＿＿＿＿

three minutes ago． Except for stopping the clock，the quake    60．＿＿＿＿

had only thrown a key from the mantel（壁炉架） to the floor．   61． ＿＿＿＿

The clock had stopped because John put some long                 62． ＿＿＿＿

glass tube he was using for an experiment into the case          63． ＿＿＿＿

for safekeeping．The quake had been knocked the tubes over and   64． ＿＿＿＿

blocked the pendulum（钟摆）． So John had the exactly

time of the earthquake．                                          65． ＿＿＿＿
 

参考答案：
56．In→On             57．第二个a→the          58．found后加it   

59．去掉第一个to      60．ago→before       61．√      62．put前加had   

63．tube→tubes              64．去掉been               65．exactly→exact