问题
选择题
As a teacher, I seldom give my students so difficult a problem ________ they can not work out.[ ]
A. that
B. if
C. in order that
D. as
答案
答案:D
As a teacher, I seldom give my students so difficult a problem ________ they can not work out.[ ]
A. that
B. if
C. in order that
D. as
答案:D