— 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
I’m sure Wang Lin is ____ to come to my aid this afternoon.
#4540
A
possible
B
likely
C
probable
D
maybe
Carbon dioxide ___ from burning fuels is the most common of the so-called greenhouse gases.
#4678
A
producing
B
having been produced
C
to be produced
D
produced
Is this the website_______ you want to have ____ into your files to help you learn English?
#4969
A
who; to add
B
that; add
C
whom; adding
D
that; added
The research showed beyond ________ that smoking contributes to heart diseases.
#4940
A
wonder
B
doubt
C
problem
D
use