— Lucy looks blue today. — Yes, but I do
问题:
— Lucy looks blue today.
— Yes, but I don't know what it is________makes herso upset. [ ]
A. as
B. what
C. that
D. which
— Lucy looks blue today.
— Yes, but I don't know what it is________makes herso upset. [ ]
A. as
B. what
C. that
D. which