A.marriedperson
B.middleschoolstudent
C.collegestudent
D.ateacher
A.essential
B.impossible
C.valuable
D.unavoidable
A.thepeopletherearegoodtoothers
B.somepeopleadvisehim/hertodoso
C.theinstituteisfreeofcharge
D.theinstituteishelpfultohis/herfuture
A.clean
B.keep
C.weaken
D.refresh
A.and
B.or
C.but
D.so
A.drive
B.shift
C.put
D.drag