He looked quite healthy though he was （ ）.
（A）in seventy
（B）in his seventies
（C）at seventies
（D）in the age of seventy
（ ） the students usually surf the Internet and get information.
（A）60 percents of
（B）60 percent
（C）60 percent of
（D）60 percents
The （ ） paragraphs are very important.
（A）one third
（B）first one
（C）first three
（D）one three
