Some Math problems are        difficult for the students         work out.
#53037
A
so, that
B
not, but
C
such, that
D
too, to
推荐题目
Lily is        her pen, but she can’t        it.
#58901
A
finding; look for
B
looking for; find
C
look for; finding
D
looking for; finding.
—How long can I _____ the book?—For four days.
#51997
A
borrow
B
to borrow
C
keep
D
to keep