— Why are you so popular with your students?— As a teacher, I seldom give my students so difficult a problem ____ they cannot work out.
#4683
A
as
B
that
C
if
D
which
推荐题目
Choosing a college major can be a difficult task, but it is nothing to take .
#4591
A
slightly
B
lightly
C
seriously
D
hardly
The girl often helps her best friend, ______ is not good at English.
#4549
A
which
B
who
C
what
D
where
—Dad, I have finished my assignment. —Good, and _________ you play or watch TV, you mustn’t disturb me.
#5008
A
whenever
B
whether
C
whatever
D
no matter