1.   I am sorry my reply is so brief, but having just cut my thumb I am unable to continue writing.

2.   I accidentally cut my thumb.

3.   She visited him two days later, just after he had cut his thumb on the mouse-trap and was bleeding into the sink.

4.   Early on, tense, he cut a thumb on the blade in his Cuisinart.

5.   Workers grabbed the man, who cut his thumb on broken glass but was not otherwise injured.

6.   And somehow he cut his thumb.