The problem is         difficult for me        work out.
#51005
A
very; to
B
enough; to
C
so; that
D
too; to
推荐题目
Thank you for ________to let me _______on the trip.
#51073
A
agree, going
B
agreeing, to go
C
agreeing, go
D
agree, go
Students should learn how        problems.
#49250
A
solve
B
solving
C
can solve
D
to solve