Lesson Three is __ most difftcult lesson, but it isn't __ most difficult lesson in Book Two.A.a;a B.a;the C. the;the D.the;a

问题描述:

Lesson Three is __ most difftcult lesson, but it isn't __ most difficult lesson in Book Two.
A.a;a B.a;the C. the;the D.the;a