根据句意，写出括号内所给单词的适当形式。
Her mother seemed even_______ after she heard the bad news. (sad)
I think we should learn from Comrade Lei Feng and think less of______ than others. (we)
He plans to go abroad for ________ study after he finishes his college.（far）
The ticket is_________(use) now. However, I’ll keep it.