请帮忙填空:Which of these do you think is ---useful invention?
请帮忙填空:Which of these do you think is ---useful invention?
Which of these do you think is the most useful invention?中do
Which of these do you think is ____ useful invention? [ 
WHICH OF THESE DO YOUTHINK IS THESECONDMOST USEFUL INVENTION
What do you think is the most useful invention?这句中do you thi
what do you think is the most useful invention in the world
连词成句 What do useful you think invention is the fourth most
Do you think what invention is the most useful 这句话对吗
Which of these microorganisms is useful?
which is the most useful great inventions?what do you think?
which do you think is more useful,a vocational education or
A:____ do you think is the most interesting invention?