I don't know much about the Sydney mines, but from the context, I can infer that the tunnels were unsafe. Whether being that they were collapsing, or they were filled with poisonous gasses.
I think the complete question would be;
Which technique is the author using in this passage to reveal the character’s traits?
passage from the grapes of wrath muley’s face was smooth and unwrinkled, but it wore the hateful look of a bad child. the mouth was held tight and small, the little eyes half scowling, half fretful.
is:
<em>the Imagery used in describing the details about the face, and the metaphor used in comparing it to a child's face. These details tell the reader about the character's personality.</em>
Sheila and Jean are both the indirect object. Book is the direct object
The public are swine That is a metaphor because it is comparing the public to pics without using like and or as.
I think it would most likey be the 3rd one