I would say that it depends on the audience. Personally, a debate regarding ethics and moral dilemma is interesting. Read The Fat Man and the Impending Doom. It's just one paragraph so it's not going to bore audience.
https://thedailydilemma.wordpress.com/2007/06/18/fat-man/
I believe that this type is a lecture-forum discussion.
Answer:
<em>The error in the sentence is using double negatives.</em>
Explanation:
Yes, there is a mistake in this sentence. The error is using double negatives in the same sentence. Double negative is making use of two negative words in a phrase like “I didn’t do nothing”, but in this double usage of negatives words they are canceling each other as if it is affirming that “I did something”. The correct construction for the sentence above should be “I don’t know about the kind of machines used to make roads.” or “I know nothing about the kind of machines used to make roads.”
