So absorbedin the experiment that he didn’t even notice it was already over 12 o’clock.A.

问题补充：

So absorbedin the experiment that he didn’t even notice it was already over 12 o’clock.

A. did he

B. he did

C. was he

D. he was

答案：

A. did he

B. he did

(答案→)C. was he

D. he was

解析：考察部分倒装句。当“so+形容词/副词”或者“such+名词”放在句首的时候，后面的主句使用部分倒装的形式。固定搭配be absorbed in专注于..；句意：他如此专注于实验，以至于他没有注意点已经12点了。故C正确。