21. _____ global financial crisis of 2008 is _____ major financial crisis, the worst of its kinds since ______ Great Depression.
A. The; a; the B. The; the; / C. A; the; the D. A; a; /
22.--You've made great progress in your studies of maths, 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
