+Explanation+.—A preposition is wanting. That = in which. (Can you find a word that would here sound better than that?)
13. Attention is the stuff that memory is made of. 14. It is to you that I speak.
+Explanation+.—Here the preposition, which usually would stand last in the sentence, is found before the complement of the independent clause. In analysis restore the preposition to its usual place—It is you that I speak to. That I speak to modifies the subject.
15. It was from me that he received the information.
(Me must be changed to I when from is restored to its usual position.)
16. Islands are the tops of mountains whose base is in the bed of the
ocean.
mountains
—————-
`
` base | is
` ———|——-
` \
`…..\whose
+Explanation+.—The connecting pronoun is here a possessive modifier of base.
17. Unhappy is the man whose mother does not make all mothers interesting.
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