Question

--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

Answer 1

C

 remain作系动词用，本身不用于被动语态，有时与不定式的被动结构构成合成谓语，意为"尚待"。