Building artificial coral reefs maybe?
Tom asks Huck to take a shirt from the clothesline which Jim can use as a journal while he is in prison. Huck is surprised, because Jim can't even write.
“whose father worked for the railroad” is a subordinate clause as it is a relative clause beginning with the pronoun “whose”. It is particularly used in written English and it refers to possession of things or to make association or connections with other things or people.
D : preceded by preposition
