— 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
Go and see her whenever _____. 
#4729
A
it will be convenient to you
B
you will be convenient
C
it is convenient to you
D
you are convenient
Our football team’s ____ has been excellent during the whole year.
#4826
A
demand
B
master
C
history
D
performance
—Sorry, I made a mistake again.— ______. Practice more and you’ll succeed.
#4876
A
Never mind
B
Certainly not
C
Not at all
D
Don’t mention it