— You’ve made great progress in your studies of English, haven’t you?
—Yes, but much .
A. remains to do
B. is remained to do
C. remains to be done
D. is remained to be done
网友回答
A. remains to do
B. is remained to do
(答案→)C. remains to be done
D. is remained to be done
解析：remain作连系动词用，本身不用于被动语态，有时与不定式的被动结构构成复合谓语，意为“尚待”。如:A number of problems remain to be solved.