Translation:The man uses his tooth when he eats.
Is there a part of Denmark where people stereotypically only have one tooth? We definitely have that place in the US...
This specific question is obviously there to sharpen one's sense for singular/plural. I typed "his teeth" (which was wrong), not noticing that it should be "his tooth". The next time I will not fall for this.
I love the Dr. Who quality to these exercises. It keeps me going through the boring stuff.