次の文の下線部と同じ用法の不定詞を含む文をad から
(1) It is impossible to live without water. ad ind
(2) Shall I bring you something to eat?
(3) Ken went to the park to play baseball.
(4) I am very happy to hear from you.
a. We must run to get there in time.
b. There is no reason to refuse your proposal.
c. They got upset to read the article.
d. My hobby is to play the violin.